chore(xilinx): replace ATF with TFA

Since the Arm Trusted Firmware(ATF) has been renamed to Trusted
Firmware-A (TF-A), replace all the instances of ATF from code comments,
macros, variables and functions to TF-A.

Change-Id: Iab448d96158612a3effb4e49943f8d6cb43aaad5
Signed-off-by: Prasad Kummari <prasad.kummari@amd.com>
Signed-off-by: Akshay Belsare <akshay.belsare@amd.com>
10 files changed