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/resources/diagrams/Makefile b/docs/resources/diagrams/Makefile
index de7d8f3..7f583b5 100644
--- a/docs/resources/diagrams/Makefile
+++ b/docs/resources/diagrams/Makefile
@@ -1,10 +1,10 @@
 #
-# Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2015-2019, Arm Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
 #
-# This Makefile generates the image files used in the ARM Trusted Firmware
+# This Makefile generates the image files used in the Trusted Firmware-A
 # document from the dia file.
 #
 # The PNG files in the present directory have been generated using Dia version