Nuvoton: Support watchdog on M251/M261 series ...

Support watchdog on below targets:
-   NUMAKER_IOT_M263A
-   NUMAKER_IOT_M252

Merge pull request #14721 from OpenNuvoton/nuvoton_no-hxt-lxt ...

Nuvoton: Enable no HXT/LXT configurability

M2354: Default to HXT not present ...

1.  Build TF-M v1.3 with GNUARM and HXT not present.
2.  Support configurability of HXT presence (targets.json).
3.  Default HXT to not present (targets.json). This must align with built TF-M secure code above.

M2354: Synchronize platform extra secure files from TF-M ...

These files are refactored on TF-M and make no logic change on Mbed.

M2354: Refine TF-M import readme ...

Add bug report of GNU Arm Embedded Toolchain 10-2020-q4-major in CMSE support

Nuvoton: Explicitly disable HXT/LXT on configured to not present ...

This is to guard from BSP driver which cannot see this configuration and still uses HXT/LXT.

Nuvoton: Enable no HXT/LXT configurabiliy ...

LXT/HXT are external crystl oscillator and can be absent on custom board.
This enables configuring LXT/HXT presence:
1.  By default, LXT/HXT are configured to be present, except M252 which has no HXT.
2.  When LXT is configured to not present, lp_ticker/watchdog will clock by LIRC instead.
3.  Limitations:
    (1) On all targets, LIRC-clocked lp_ticker gets inaccurate and fails to pass tests.
    (2) On NUC472/M453, HIRC-clocked PLL doesn't output 1MHz-aligned frequency. us_ticker gets slight inaccurate.
    (3) On all targets, LIRC-clocked RTC is not supported due to no H/W path/RTC clock source reset to LXT on reset/RTC not trimmed for other clock rates.
4.  On M263, TRNG's clock source defaults to LXT and needs special handling without LXT.
5.  On M252, replace target.hxt-enable with target.hxt-present for consistency.

M2354: Comply with standard pin naming rule

M2354: Update to TF-M 1.3

M2354: Refine TF-M/Mbed integration readme

M2354: Use TF-M exported region_defs.h to replace target.mbed_rom_start and friends

M2354: Support TRNG as entropy source on TF-M ...

1.  Update TF-M Secure bin enabling TRNG as entropy source
2.  Replaced with above, remove TRNG HAL stuff on Mbed, including platform extra secure functions, cmake, etc.

M2354: Reduce output image size ...

1.  Enable mcuboot no padding option
2.  Support output image format Intel Hex

M2354: Add serial_tx_empty(...) ...

Enable serial sync with the below PR:
https://github.com/ARMmbed/mbed-os/pull/14600

M2354: Support TF-M ...

1.  Configure non-secure target name to NU_M2354 (targets/targets.json). No NU_M2354_NS alias
2.  Following template target, enable image signing and concatenating in post-build process
    (1) Add post-build script (tools/targets).
    (2) Enable TF-M custom build by centralize relevant stuff imported from TF-M (COMPONENT_TFM_S_FW).
3.  Add M2354Code.merge_secure into whitelist of uvision6 (tools/export/uvision/__init__.py).
4.  Add M2354 CMSIS pack database (tools/arm_pack_manager/index.json).
5.  Configure stdio baudrate to 115200 to match TF-M port (platform/mbed_lib.json).
6.  Define CMSIS_NVIC_VIRTUAL to override NVIC_SystemReset with TF-M version (cmsis_nvic_virtual.h).
7.  Override tfm_ns_interface_xxx(...) to enable NS secure call:
    (1) At pre-rtos stage
    (2) In SVC context
8. Implement secure function call with tfm_platform_ioctl(...).
9. Combine stddriver_secure.h/c and hal_secure.h/c into platform_extra_secure.h/c.
10. Fix peripheral base to non-secure (PeripheralNames.h) (TrustZone-unaware since Mbed OS 6.0).
11. Fix NU_PORT_BASE/NU_GET_GPIO_PIN_DATA/NU_SET_GPIO_PIN_DATA to non-secure (PinNamesCommon.h) (TrustZone-unaware since Mbed OS 6.0).
12. NSC convention for StdDriver sys/clk (both TF-M and Mbed must follow)
    (1) SYS_ResetModule
        Usage: Replaced with SYS_ResetModule_S on Mbed OS
        Action: Make it inaccessible from Mbed (neither source nor NSC). Provide SYS_ResetModule_S on Mbed via platform ioctl instead.
    (2) CLK_GetXxx
        Usage: Called in bpwm/i2s/qspi/sc/sdh and system_M2354 on Mbed OS
        Action: Make them inaccessible from Mbed (neither source nor NSC). Re-provide them on Mbed via platform ioctl instead.
13. Remove DISABLE/ENABLE macro definitions in BSP to avoid name conflict with other modules
14. Change to TMR4/5 from TMR2/3 for implementing us_ticker/lp_ticker because TMR2 is used for TF-M NSPE test
15. Support cmake

NOTE: Export(uvision6) doesn't support TF-M target. To enable it for partial compile on Keil, force below function to return true.
      is_target_supported(tools/export/uvision/__init__.py)

Merge pull request #14567 from OpenNuvoton/nvt_m480_wdt_rst ...

M487: Resolve WDT reset H/W limit

M487: Refine the WKT resolution to WDT reset from PD ...

1. Rephrase the comment
2. Pass WDT reset reason test

Align lines by space instead of tab

Resolve M480 WDT reset H/W limit by reset from deep power-down

Nuvoton: Fix hal_watchdog_kick() with WDT stopped ...

According to HAL spec, hal_watchdog_kick() shall do nothing when WDT is stopped.

M487: Adjust placement of SYS_UnlockReg in WDT reset from PD patch ...

This adjustment has two purposes:
1.  Avoid misleading placement of SYS_UnlockReg for WDT clock setting
2.  Safer for power-down

Update UART pin names & add MBED_CONF_TARGET_STDIO_UART overrides

Remove unused NUVOTON M2351 target files

Add standard pin-names validation script & tests

Merge pull request #14379 from OpenNuvoton/nvt_high_res_pwm ...

Nuvoton: Enlarge NuMaker PWM duty cycle range

To keep proprietary BSP DutyCycle definition and rename HighDutyCycle in extend API

Add bare metal support to Nuvoton targets ...

Modify `targets.json` to configure bare metal for the following targets:
NUMAKER_IOT_M252, NUMAKER_IOT_M263A, NUMAKER_IOT_M487, NUMAKER_PFM_M487,
NUMAKER_PFM_NUC472. Add target link interface between nuvoton library
and mbed-cmsis-cortex-m.

Remove uARM dependencies from Nuvoton targets

Support M251/M261/M453/NANO130/NUC472 PWM duty cycle range as 0 ~ 10000

Support M480 PWM duty cycle range as 0 ~ 10000