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>

Make TF UUID RFC 4122 compliant ...

RFC4122 defines that fields are stored in network order (big endian),
but TF-A stores them in machine order (little endian by default in TF-A).
We cannot change the future UUIDs that are already generated, but we can store
all the bytes using arrays and modify fiptool to generate the UUIDs with
the correct byte order.

Change-Id: I97be2d3168d91f4dee7ccfafc533ea55ff33e46f
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>

fip: move headers shared between TF and fiptool to include/tools_share ...

Some header files need to be shared between TF and host programs.
For fiptool, two headers are copied to the tools/fiptool directory,
but it looks clumsy.

This commit introduces a new directory, include/tools_share, which
collects headers that should be shared between TF and host programs.

This will clarify the interface exposed to host tools.  We should
add new headers to this directory only when we really need to do so.

For clarification, I inserted a blank line between headers from the
include/ directory (#include <...>) and ones from a local directory
(#include "..." ).

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>