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/plat/poplar.rst b/docs/plat/poplar.rst
index 0129478..5884ed9 100644
--- a/docs/plat/poplar.rst
+++ b/docs/plat/poplar.rst
@@ -5,7 +5,7 @@
 Edition TV Platform specification.
 
 The board features the Hi3798C V200 with an integrated quad-core 64-bit
-ARM Cortex A53 processor and high performance Mali T720 GPU, making it capable
+Arm Cortex A53 processor and high performance Mali T720 GPU, making it capable
 of running any commercial set-top solution based on Linux or Android.
 
 It supports a premium user experience with up to H.265 HEVC decoding of 4K
@@ -14,7 +14,7 @@
 ::
 
     SOC Hisilicon Hi3798CV200
-    CPU Quad-core ARM Cortex-A53 64 bit
+    CPU Quad-core Arm Cortex-A53 64 bit
     DRAM DDR3/3L/4 SDRAM interface, maximum 32-bit data width 2 GB
     USB Two USB 2.0 ports One USB 3.0 ports
     CONSOLE USB-micro port for console support
@@ -28,11 +28,11 @@
 
 At the start of the boot sequence, the bootROM executes the so called l-loader
 binary whose main role is to change the processor state to 64bit mode. This
-must  happen prior invoking the arm trusted  firmware:
+must happen prior to invoking Trusted Firmware-A:
 
 ::
 
-    l-loader --> arm_trusted_firmware --> u-boot
+    l-loader --> Trusted Firmware-A --> u-boot
 
 How to build
 ============
@@ -40,7 +40,7 @@
 Code Locations
 --------------
 
--  ARM Trusted Firmware:
+-  Trusted Firmware-A:
    `link <https://github.com/ARM-software/arm-trusted-firmware>`__
 
 -  l-loader: