fix(zynqmp): resolve coverity warnings

Fix for coverity issues in pm_service component.
Fixed compilation error for versal platform.

Change-Id: I948f01807e67ad1e41021557e040dcbfb7b3a39e
Signed-off-by: HariBabu Gattem <haribabu.gattem@amd.com>
Signed-off-by: Naman Patel <naman.patel@amd.com>
diff --git a/plat/xilinx/zynqmp/include/plat_ipi.h b/plat/xilinx/zynqmp/include/plat_ipi.h
index bccd2f1..a78f93a 100644
--- a/plat/xilinx/zynqmp/include/plat_ipi.h
+++ b/plat/xilinx/zynqmp/include/plat_ipi.h
@@ -41,7 +41,7 @@
 #define IPI_BUFFER_TARGET_LOCAL_OFFSET	0x80U
 #define IPI_BUFFER_TARGET_REMOTE_OFFSET	0x1C0U
 
-#define IPI_BUFFER_MAX_WORDS	8
+#define IPI_BUFFER_MAX_WORDS	8U
 
 #define IPI_BUFFER_REQ_OFFSET	0x0U
 #define IPI_BUFFER_RESP_OFFSET	0x20U