Sanitise includes across codebase ...

Enforce full include path for includes. Deprecate old paths.

The following folders inside include/lib have been left unchanged:

- include/lib/cpus/${ARCH}
- include/lib/el3_runtime/${ARCH}

The reason for this change is that having a global namespace for
includes isn't a good idea. It defeats one of the advantages of having
folders and it introduces problems that are sometimes subtle (because
you may not know the header you are actually including if there are two
of them).

For example, this patch had to be created because two headers were
called the same way: e0ea0928d5b7 ("Fix gpio includes of mt8173 platform
to avoid collision."). More recently, this patch has had similar
problems: 46f9b2c3a282 ("drivers: add tzc380 support").

This problem was introduced in commit 4ecca33988b9 ("Move include and
source files to logical locations"). At that time, there weren't too
many headers so it wasn't a real issue. However, time has shown that
this creates problems.

Platforms that want to preserve the way they include headers may add the
removed paths to PLAT_INCLUDES, but this is discouraged.

Change-Id: I39dc53ed98f9e297a5966e723d1936d6ccf2fc8f
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

SPM: Remove remaining SMC interfaces ...

Also, add a disclaimer to explain that the current implementation of SPM
is a prototype that is going to undergo a lot of rework.

Change-Id: I303c1e61c51d9f286cc599fea565fc9ba5a996bf
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Standardise header guards across codebase ...

All identifiers, regardless of use, that start with two underscores are
reserved. This means they can't be used in header guards.

The style that this project is now to use the full name of the file in
capital letters followed by 'H'. For example, for a file called
"uart_example.h", the header guard is UART_EXAMPLE_H.

The exceptions are files that are imported from other projects:

- CryptoCell driver
- dt-bindings folders
- zlib headers

Change-Id: I50561bf6c88b491ec440d0c8385c74650f3c106e
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

SPM: Allow entering the SP without needing a SMC ...

It may be needed to enter the Secure Partition through other means than
an MM_COMMUNICATE SMC. This patch enables this behaviour by extracting
the necessary code from mm_communicate() and allowing other parts of the
code to use it.

Change-Id: I59f6638d22d9c9d0baff0984f39d056298a8dc8e
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

SPM: Fix version header definitions ...

Rename SP_VERSION macros to MM_VERSION, which is the name used in the MM
specification [1]. Also, a few more helper macros have been added.

MM-specific definitions have been moved to their own header file.

[1] http://infocenter.arm.com/help/topic/com.arm.doc.den0060a/DEN0060A_ARM_MM_Interface_Specification.pdf

Change-Id: Ia10e48c7e81a7a1f5eeca29a5270cae740a4a88a
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

SPM: Rename SP_COMMUNICATE macros ...

Rename SP_COMMUNICATE_AARCH32/AARCH64 into MM_COMMUNICATE_AARCH32/AARCH64
to align with the MM specification [1].

[1] http://infocenter.arm.com/help/topic/com.arm.doc.den0060a/DEN0060A_ARM_MM_Interface_Specification.pdf

Change-Id: I478aa4024ace7507d14a5d366aa8e20681075b03
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>

SPM: Rename SP_MEM_ATTR*** defines ...

The defines have been renamed to match the names used in the
documentation.

Change-Id: I2f18b65112d2db040a89d5a8522e9790c3e21628
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

SPM: Introduce Secure Partition Manager ...

A Secure Partition is a software execution environment instantiated in
S-EL0 that can be used to implement simple management and security
services. Since S-EL0 is an unprivileged exception level, a Secure
Partition relies on privileged firmware e.g. ARM Trusted Firmware to be
granted access to system and processor resources. Essentially, it is a
software sandbox that runs under the control of privileged software in
the Secure World and accesses the following system resources:

- Memory and device regions in the system address map.
- PE system registers.
- A range of asynchronous exceptions e.g. interrupts.
- A range of synchronous exceptions e.g. SMC function identifiers.

A Secure Partition enables privileged firmware to implement only the
absolutely essential secure services in EL3 and instantiate the rest in
a partition. Since the partition executes in S-EL0, its implementation
cannot be overly complex.

The component in ARM Trusted Firmware responsible for managing a Secure
Partition is called the Secure Partition Manager (SPM). The SPM is
responsible for the following:

- Validating and allocating resources requested by a Secure Partition.
- Implementing a well defined interface that is used for initialising a
  Secure Partition.
- Implementing a well defined interface that is used by the normal world
  and other secure services for accessing the services exported by a
  Secure Partition.
- Implementing a well defined interface that is used by a Secure
  Partition to fulfil service requests.
- Instantiating the software execution environment required by a Secure
  Partition to fulfil a service request.

Change-Id: I6f7862d6bba8732db5b73f54e789d717a35e802f
Co-authored-by: Douglas Raillard <douglas.raillard@arm.com>
Co-authored-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
Co-authored-by: Achin Gupta <achin.gupta@arm.com>
Co-authored-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>