Update Arm TF references to TF-A

Update Arm Trusted Firmware references in the upstream documents to
Trusted Firmware-A (TF-A). This is for consistency with and
disambiguation from Trusted Firmware-M (TF-M).

Also update other Arm trademarks, e.g. ARM->Arm, ARMv8->Armv8-A.

Change-Id: I8bb0e18af29c6744eeea2dc6c08f2c10b20ede22
Signed-off-by: Dan Handley <dan.handley@arm.com>
Signed-off-by: David Cunado <david.cunado@arm.com>
diff --git a/docs/psci-pd-tree.rst b/docs/psci-pd-tree.rst
index 329106c..1113abc 100644
--- a/docs/psci-pd-tree.rst
+++ b/docs/psci-pd-tree.rst
@@ -1,4 +1,4 @@
-PSCI Library Integration guide for ARMv8-A AArch32 systems
+PSCI Library Integration guide for Armv8-A AArch32 systems
 ==========================================================
 
 
@@ -309,4 +309,4 @@
 
 --------------
 
-*Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.*
+*Copyright (c) 2017-2018, Arm Limited and Contributors. All rights reserved.*