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/Makefile b/Makefile
index 471cf59..c4ff53f 100644
--- a/Makefile
+++ b/Makefile
@@ -510,9 +510,8 @@
 # Process platform overrideable behaviour
 ################################################################################
 
-# Using the ARM Trusted Firmware BL2 implies that a BL33 image also needs to be
-# supplied for the FIP and Certificate generation tools. This flag can be
-# overridden by the platform.
+# Using BL2 implies that a BL33 image also needs to be supplied for the FIP and
+# Certificate generation tools. This flag can be overridden by the platform.
 ifdef BL2_SOURCES
         ifdef EL3_PAYLOAD_BASE
                 # If booting an EL3 payload there is no need for a BL33 image