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>

Add Trusted OS extra image parsing support for ARM standard platforms ...

Trusted OS may have extra images to be loaded. Load them one by one
and do the parsing. In this patch, ARM TF need to load up to 3 images
for optee os: header, pager and paged images. Header image is the info
about optee os and images. Pager image include pager code and data.
Paged image include the paging parts using virtual memory.

Change-Id: Ia3bcfa6d8a3ed7850deb5729654daca7b00be394
Signed-off-by: Summer Qin <summer.qin@arm.com>