Remove references to old project name from common files

The project has been renamed from "Arm Trusted Firmware (ATF)" to
"Trusted Firmware-A (TF-A)" long ago. A few references to the old
project name that still remained in various places have now been
removed.

This change doesn't affect any platform files. Any "ATF" references
inside platform files, still remain.

Change-Id: Id97895faa5b1845e851d4d50f5750de7a55bf99e
Signed-off-by: John Tsichritzis <john.tsichritzis@arm.com>
diff --git a/docs/change-log.rst b/docs/change-log.rst
index 4ef3ac1..70aafc0 100644
--- a/docs/change-log.rst
+++ b/docs/change-log.rst
@@ -632,8 +632,8 @@
 
    -  Introduce External Abort handling on AArch64
       External Abort routed to EL3 was reported as an unhandled exception
-      and caused a panic. This change enables Arm Trusted Firmware-A to
-      handle External Aborts routed to EL3.
+      and caused a panic. This change enables Trusted Firmware-A to handle
+      External Aborts routed to EL3.
 
    -  Save value of ACTLR_EL1 implementation-defined register in the CPU
       context structure rather than forcing it to 0.