libc: Move tf_printf and tf_snprintf to libc ...

Change their names to printf and snprintf. They are much smaller than
the previous versions we had, which makes them better suited for the
Trusted Firmware.

Change-Id: Ia872af91b7b967c47fce012eccecede7873a3daf
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

libc: Add AArch32 and AArch64 headers ...

Change-Id: I4f58bb4660078c9bc76d2826c90b2fa711719a3e
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

libc: Cleanup remaining files ...

The existing files had some style problems that this patch fixes.

Change-Id: I794e0d96e52f8da0ffa0d70a41f36c4432b4e563
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

libc: Remove sscanf() and timingsafe_bcmp() ...

sscanf() is unused and it doesn't work, so it doesn't make sense to
keep it.

timingsafe_bcmp() isn't used anywhere.

Change-Id: Ib5d28ff21d0f3ccc36c5c0fb5474b3384105cf80
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

Create a library file for libc ...

TF Makefile was linking all the objects files generated for the
c library instead of creating a static library that could be
used in the linking stage.

Change-Id: I721daea097e9b13cbb42c9f8eaa2af8fea0799cf
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>