arm/trusted-firmware-a: drop clang tweaks

These Clang patches don't appear to be needed anymore.  TF-A doesn't
build for various platforms but the unusual errors these patches work
around are not the cause.

Change-Id: I41dffc4f19d298d5861bb0274e6ffef6c24f4ca3
Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Jon Mason <jon.mason@arm.com>