fix(versal): platform definition of invalid entry

Add platform specific function to return custom entry address.

Change-Id: I58785a8b7c197e4dae3ac9a29f8d23c29d5cb5e3
Signed-off-by: Maheedhar Bollapalli <maheedharsai.bollapalli@amd.com>
diff --git a/plat/xilinx/versal/versal_setup.c b/plat/xilinx/versal/versal_setup.c
index 35589ab..fb952f9 100644
--- a/plat/xilinx/versal/versal_setup.c
+++ b/plat/xilinx/versal/versal_setup.c
@@ -79,3 +79,8 @@
 {
 	return mmap;
 }
+
+uintptr_t plat_get_invalid_addr(void)
+{
+	return (uintptr_t)PLAT_DDR_LOWMEM_MAX;
+}