fix(zynqmp): resolve the misra 4.6 warnings

MISRA Violation: MISRA-C:2012 R.4.6
- Using basic numerical type int rather than a typedef
that includes size and signedness information.

Change-Id: Id85e69b29b124052b4a87462ce27fcdfc00c13c9
Signed-off-by: HariBabu Gattem <haribabu.gattem@amd.com>
diff --git a/plat/xilinx/common/ipi.c b/plat/xilinx/common/ipi.c
index 318079b..6438896 100644
--- a/plat/xilinx/common/ipi.c
+++ b/plat/xilinx/common/ipi.c
@@ -141,7 +141,7 @@
  */
 int ipi_mb_enquire_status(uint32_t local, uint32_t remote)
 {
-	int ret = 0;
+	int ret = 0U;
 	uint32_t status;
 
 	status = mmio_read_32(IPI_REG_BASE(local) + IPI_OBR_OFFSET);