feat(zynqmp): enable ENABLE_LTO flag

Enabling Link Time Optimization in platform.mk for AMD-Xilinx
ZynqMP platform optimizes TF-A size.
With ENABLE_LTO=0, the release bl31.elf size is 86098.
With ENABLE_LTO=1, the release bl31.elf size reduces to 81866.
The size difference in OCM is 4232 bytes, saving up to 4KB.

Signed-off-by: Prasad Kummari <prasad.kummari@amd.com>
Change-Id: I6d5001a9ac250e3a87b958e9b665962a917265d6

plat/xilinx/zynqmp/platform.mk

@@ -2,7 +2,7 @@
 # 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.
+# Copyright (c) 2022-2024, Advanced Micro Devices, Inc. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
@@ -16,6 +16,7 @@ ZYNQMP_WDT_RESTART := 0
 IPI_CRC_CHECK := 0
 override RESET_TO_BL31 := 1
 override WARMBOOT_ENABLE_DCACHE_EARLY := 1
+ENABLE_LTO := 1
 
 EL3_EXCEPTION_HANDLING := $(SDEI_SUPPORT)