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.

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@xilinx.com>
Change-Id: I9fb686e7aa2b85af6dfcb7bb5f87eddf469fb85c
diff --git a/plat/xilinx/zynqmp/pm_service/pm_svc_main.h b/plat/xilinx/zynqmp/pm_service/pm_svc_main.h
index abadd40..ca5ed62 100644
--- a/plat/xilinx/zynqmp/pm_service/pm_svc_main.h
+++ b/plat/xilinx/zynqmp/pm_service/pm_svc_main.h
@@ -9,7 +9,7 @@
 
 #include "pm_common.h"
 
-int pm_setup(void);
+int32_t pm_setup(void);
 uint64_t pm_smc_handler(uint32_t smc_fid, uint64_t x1, uint64_t x2, uint64_t x3,
 			uint64_t x4, void *cookie, void *handle,
 			uint64_t flags);