fix(zynqmp): resolve misra R10.3

MISRA Violation: MISRA-C:2012 R.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.

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@xilinx.com>
Change-Id: I5a60c66788d59e45f41ceb81758b42ef2df9f5f7
diff --git a/plat/xilinx/zynqmp/sip_svc_setup.c b/plat/xilinx/zynqmp/sip_svc_setup.c
index 114da33..ac938b6 100644
--- a/plat/xilinx/zynqmp/sip_svc_setup.c
+++ b/plat/xilinx/zynqmp/sip_svc_setup.c
@@ -100,6 +100,6 @@
 		sip_svc,
 		OEN_SIP_START,
 		OEN_SIP_END,
-		SMC_TYPE_FAST,
+		(uint8_t)SMC_TYPE_FAST,
 		sip_svc_setup,
 		sip_svc_smc_handler);