feat(intel): add intel_rsu_update() to sip_svc_v2

Add smc function id for intel_rsu_update() in sip_svc_v2. For temporarily
saving the RSU application image address before a cold reset is
issued.

Signed-off-by: Mahesh Rao <mahesh.rao@intel.com>
Signed-off-by: Jit Loon Lim <jit.loon.lim@intel.com>
Change-Id: I43bc7bd5aa5fa9238bceba1d826bf0a34ff87adb
diff --git a/plat/intel/soc/common/socfpga_sip_svc.c b/plat/intel/soc/common/socfpga_sip_svc.c
index ff050e4..1a18ee1 100644
--- a/plat/intel/soc/common/socfpga_sip_svc.c
+++ b/plat/intel/soc/common/socfpga_sip_svc.c
@@ -442,7 +442,7 @@
 	return INTEL_SIP_SMC_STATUS_OK;
 }
 
-static uint32_t intel_rsu_update(uint64_t update_address)
+uint32_t intel_rsu_update(uint64_t update_address)
 {
 	if (update_address > SIZE_MAX) {
 		return INTEL_SIP_SMC_STATUS_REJECTED;