CMake: Move lorawan stubs to the lorawan dir ...

Move the connectivity lorawan stubs into the connectivity/lorawan
component directory. So we can avoid duplicating the mbed-os source
tree in a central UNITTESTS folder.

CMake: unit-tests: Move mbed-headers-hal to the hal directory ...

Move the header-only mbed-headers-hal library the unit test stubs
depend on into the hal component directory. This makes the events
stubs more self-contained and improves the composition of the library.

CMake: Move hal stubs sources to the mbed-os/hal directory ...

Move the hal stubs into the hal component directory.
so we can avoid duplicating the mbed-os source tree in a central
UNITTESTS folder.

CMake: unit-tests: Add mbed-headers-cellular headers library ...

- Previously all cellular header made as a part of the
mbed-headers-connectivity library. To make it easier to separate all
the cellular headers into the separate mbed-headers-cellular library
and keep them as part of cellular stub CMake. This makes the cellular
stubs more self-contained and improves the composition of the library.
- Update all unit test that depends on cellular headers with mbed-headers-cellular library

CMake: Move connectivity/cellular stubs to the mbed-os/connectivity/cellular dir ...

Move the connectivity cellular into the connectivity/cellular component
directory. So we can avoid duplicating the mbed-os source tree in a
central UNITTESTS folder.

Merge pull request #14819 from ARMmbed/move_rtos_stubs ...

Move rtos stubs to the rtos directory

Merge pull request #14716 from boraozgen/at-handler-buffer-size-config ...

Cellular: Add AT handler buffer size to configuration

CMake: unit-tests: Update connectivity stubs and their unittests ...

mbed-stubs-connectivity now depends on the mbed-stubs-rtos and
mbed-stubs-rtos-headers because it requires some headers and sources
which were moved to mbed-stubs-rtos and mbed-stubs-rtos-headers.

CMake: unit-tests: Move mbed-headers-rtos to the rtos directory ...

Move the header-only mbed-headers-rtos library the unit test stubs
depend on into the rtos component directory. This makes the rtos
stubs more self-contained and improves the composition of the library.

CMake: Move rtos stub headers to the rtos/tests/UNITTESTS/double directory ...

Move rtos stubs headers to the mbed-os/rtos/tests/UNITTESTS/double
directory and update CMake to create a mbed-stubs-rtos-headers
library for rtos stub headers

CMake: Move rtos stubs sources to the mbed-os/rtos directory ...

Move the rtos stub library into the rtos component directory.
so we can avoid duplicating the mbed-os source tree in a central
UNITTESTS folder.

CMake: unit-tests: Move mbed-headers-drivers to the drivers directory ...

Move the header-only mbed-headers-drivers library the unit test stubs
depend on into the drivers component directory. This makes the drivers
stubs more self-contained and improves the composition of the library.

CMake: Move drivers stubs to the mbed-os/drivers directory ...

Move the drivers stub library into the drivers component directory.
so we can avoid duplicating the mbed-os source tree in a central
UNITTESTS folder.

Cellular: Add AT handler buffer size to configuration

CMake: unit-tests: Remove trailing whitespace from stubs/CMakeLists.txt

test: Fix function does not return a value warnings ...

Many test stub functions are meant to return a value, but weren't. Clang
would generate a warning for each instance where we weren't returning
anything in a function that was meant to return a value.

    warning: non-void function does not return a value [-Wreturn-type]

For a specific example, my_radio::time_on_air() is supposed to return a
uint32_t, but wasn't returning anything. We'll return a zero instead of
relying on undefined behavior.

Without this, clang 11.0.1 was generating a virtual function
implementation with a `ud2` instruction to abort at run-time, causing
some execution of some unit tests to abort.

    Running main() from gmock_main.cc
    [==========] Running 10 tests from 1 test suite.
    [----------] Global test environment set-up.
    [----------] 10 tests from Test_LoRaPHYUS915
    [ RUN      ] Test_LoRaPHYUS915.constructor
    [       OK ] Test_LoRaPHYUS915.constructor (0 ms)
    [ RUN      ] Test_LoRaPHYUS915.restore_default_channels
    [       OK ] Test_LoRaPHYUS915.restore_default_channels (0 ms)
    [ RUN      ] Test_LoRaPHYUS915.rx_config
    [       OK ] Test_LoRaPHYUS915.rx_config (0 ms)
    [ RUN      ] Test_LoRaPHYUS915.tx_config
    Process 35669 stopped
    * thread #1, name = 'lorawan-loraphy-', stop reason = signal SIGILL: privileged instruction
        frame #0: 0x0000000000276f73 lorawan-loraphy-us915-unittest`my_radio::time_on_air(this=0x0000000800c2b048, modem=MODEM_LORA, pkt_len='\0') at Test_LoRaPHYUS915.cpp:90:5
       87       };
       88
       89       virtual uint32_t time_on_air(radio_modems_t modem, uint8_t pkt_len)
    -> 90       {
       91       };
       92
       93       virtual bool perform_carrier_sense(radio_modems_t modem,
    (lldb) disassemble --pc
    lorawan-loraphy-us915-unittest`my_radio::time_on_air:
    ->  0x276f73 <+67>: ud2
        0x276f75:       int3
        0x276f76:       int3
        0x276f77:       int3
    (lldb)

CMake: Update hal and platform stub CMake linker options for coverage ...

- Armclang is not working when we add gcov as target_link_libraries,
modified to pass as linker options with --coverage so it can work armclang and gcc

sort stubs into libraries

Lora: Add LoRaWANTimer::clear in stubs

Update unittests

pwmout - UNITTESTS - add read methods for period and pulsewidth

Update UNITTESTS header reference

Fix UNITTESTS build failure

Restructure events directory & move tests

Merge pull request #13335 from rajkan01/netsocket_dir_restructure ...

Restructure netsocket directory

Update netsocket header and source reference in other libraries

Update greentea config, header reference

Merge pull request #13264 from ashok-rao/rtos-refactor ...

Moving around a few items within \rtos

Fix UNITTESTS issue

Unittests and Astyle: ...

- Update the header reference and source reference in cmake
- Update astyleignore to ignore blockdevice UNITTESTS
- Removed the redundant debug log