fix(zynqmp): conditional reservation of memory in DTB

When the TF-A is placed in DDR memory range, the DDR memory range is
getting explicitly reserved in the default device tree by TF-A.
This creates an error condition in the use case where Device tree is
not present or it is present at a different location.

To fix this, a new build time parameter, XILINX_OF_BOARD_DTB_ADDR, is
introduced. The TF-A will reserve the DDR memory only when a valid
DTB address is provided to XILINX_OF_BOARD_DTB_ADDR during build.

Now the user has options, either manually reserve the desired
DDR address range for TF-A in device tree or let TF-A access and modify
the device tree, to reserve the DDR address range, in runtime using
the build parameter.

Change-Id: I846fa373ba9f7c984eda3a55ccaaa622082cad81
Signed-off-by: Akshay Belsare <akshay.belsare@amd.com>
diff --git a/plat/xilinx/zynqmp/platform.mk b/plat/xilinx/zynqmp/platform.mk
index 38e7408..4671f5f 100644
--- a/plat/xilinx/zynqmp/platform.mk
+++ b/plat/xilinx/zynqmp/platform.mk
@@ -1,6 +1,8 @@
 #
 # Copyright (c) 2013-2021, ARM Limited and Contributors. All rights reserved.
 # Portions copyright (c) 2021-2022, ProvenRun S.A.S. All rights reserved.
+# Copyright (c) 2018-2022, Xilinx, Inc. All rights reserved.
+# Copyright (c) 2022-2023, Advanced Micro Devices, Inc. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
@@ -75,6 +77,10 @@
     $(eval $(call add_define,ZYNQMP_SECURE_EFUSES))
 endif
 
+ifdef XILINX_OF_BOARD_DTB_ADDR
+$(eval $(call add_define,XILINX_OF_BOARD_DTB_ADDR))
+endif
+
 PLAT_INCLUDES		:=	-Iinclude/plat/arm/common/			\
 				-Iinclude/plat/arm/common/aarch64/		\
 				-Iplat/xilinx/common/include/			\