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>

zlib: add gunzip() support ...

This commit adds some more files to use zlib from TF.

To use zlib, ->zalloc and ->zfree hooks are needed.  The implementation
depends on the system.  For user-space, the libc provides malloc() and
friends.  Unfortunately, ARM Trusted Firmware does not provide malloc()
or any concept of dynamic memory allocation.

I implemented very simple calloc() and free() for this.  Stupidly,
zfree() never frees memory, but it works enough for this.

The purpose of using zlib is to implement gunzip() - this function
takes compressed data from in_buf, then dumps the decompressed data
to oub_buf.  The work_buf is used for memory allocation during the
decompress.  Upon exit, it updates in_buf and out_buf.  If successful,
in_buf points to the end of input data, out_buf to the end of the
decompressed data.

To use this feature, you need to do:

 - include lib/zlib/zlib.mk from your platform.mk

 - add $(ZLIB_SOURCES) to your BL*_SOURCES

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