fix(xilinx): typecast operands to match data type

This corrects the MISRA violation C2012-10.3:
The value of an expression shall not be assigned to an object with a
narrower essential type or of a different essential type category.
The condition is explicitly checked against 0U, appending 'U' and
typecasting for unsigned comparison.

Change-Id: I1606422aadfd64b283fd9948b6dadcddecdf61e0
Signed-off-by: Nithin G <nithing@amd.com>
Signed-off-by: Maheedhar Bollapalli <maheedharsai.bollapalli@amd.com>
diff --git a/plat/xilinx/common/versal.c b/plat/xilinx/common/versal.c
index b37dc76..7c29bae 100644
--- a/plat/xilinx/common/versal.c
+++ b/plat/xilinx/common/versal.c
@@ -60,5 +60,5 @@
  */
 int32_t plat_get_soc_revision(void)
 {
-	return (platform_id & SOC_ID_REV_MASK);
+	return (int32_t)(platform_id & SOC_ID_REV_MASK);
 }