feat(versal-net): enable assertion

Retain assertions in release builds by building TF-A with
ENABLE_ASSERTIONS=1. It helps to catch programming errors
(e.g. bad argument provided by platform porting function)
in release builds as well.
code size change is 4k.
For debug builds, assertions are enabled by default.
The same change is done by Tegra: plat/nvidia/tegra/platform.mk

Change-Id: I0db4b82d42d115866a3ed43933edbfc46ac7406a
Signed-off-by: Amit Nagal <amit.nagal@amd.com>
diff --git a/plat/xilinx/versal_net/platform.mk b/plat/xilinx/versal_net/platform.mk
index fb229bb..f299189 100644
--- a/plat/xilinx/versal_net/platform.mk
+++ b/plat/xilinx/versal_net/platform.mk
@@ -69,6 +69,9 @@
 $(eval $(call add_define,XILINX_OF_BOARD_DTB_ADDR))
 endif
 
+# enable assert() for release/debug builds
+ENABLE_ASSERTIONS := 1
+
 PLAT_INCLUDES		:=	-Iinclude/plat/arm/common/			\
 				-Iplat/xilinx/common/include/			\
 				-Iplat/xilinx/common/ipi_mailbox_service/	\