build: deprecate Arm rde1edge

Arm has decided to deprecate the rde1edge platform. The development
of software and fast model for this platform have been discontinued.
Hence, updated the makefile to warn about the deprecation of this
platform, and also reflected it in the documentation.

Change-Id: I0d44de4590dd5dce02c7c4b433df25dc438e6c49
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>

docs/plat/index.rst

@@ -76,7 +76,9 @@ Deprecated platforms
 +----------------+----------------+--------------------+--------------------+
 |    tc0         |      Arm       |        2.8         |       3.0          |
 +----------------+----------------+--------------------+--------------------+
+|    rde1edge    |      Arm       |        2.9         |       3.1          |
++----------------+----------------+--------------------+--------------------+
 
 --------------
 
-*Copyright (c) 2019-2022, Arm Limited. All rights reserved.*
+*Copyright (c) 2019-2023, Arm Limited. All rights reserved.*

plat/arm/board/rde1edge/platform.mk

@@ -1,9 +1,12 @@
 #
-# Copyright (c) 2018-2020, Arm Limited. All rights reserved.
+# Copyright (c) 2018-2023, Arm Limited. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
 
+$(warning Platform ${PLAT} is deprecated. \
+  Some of the features might not work as expected)
+
 include plat/arm/css/sgi/sgi-common.mk
 
 RDE1EDGE_BASE		=	plat/arm/board/rde1edge