Fix pointer type mismatch of handlers

Commit 4c0d03907652 ("Rework type usage in Trusted Firmware") changed
the type usage in struct declarations, but did not touch the definition
side.  Fix the type mismatch.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/plat/mediatek/common/custom/oem_svc.c b/plat/mediatek/common/custom/oem_svc.c
index 49e7571..c396e2d 100644
--- a/plat/mediatek/common/custom/oem_svc.c
+++ b/plat/mediatek/common/custom/oem_svc.c
@@ -32,14 +32,14 @@
 /*******************************************************************************
  * OEM top level handler for servicing SMCs.
  ******************************************************************************/
-uint64_t oem_smc_handler(uint32_t smc_fid,
-			uint64_t x1,
-			uint64_t x2,
-			uint64_t x3,
-			uint64_t x4,
+uintptr_t oem_smc_handler(uint32_t smc_fid,
+			u_register_t x1,
+			u_register_t x2,
+			u_register_t x3,
+			u_register_t x4,
 			void *cookie,
 			void *handle,
-			uint64_t flags)
+			u_register_t flags)
 {
 	WARN("Unimplemented OEM Call: 0x%x\n", smc_fid);
 	SMC_RET1(handle, SMC_UNK);
@@ -49,14 +49,14 @@
  * Top-level OEM Service SMC handler. This handler will in turn dispatch
  * calls to related SMC handler
  */
-uint64_t oem_svc_smc_handler(uint32_t smc_fid,
-			 uint64_t x1,
-			 uint64_t x2,
-			 uint64_t x3,
-			 uint64_t x4,
+uintptr_t oem_svc_smc_handler(uint32_t smc_fid,
+			 u_register_t x1,
+			 u_register_t x2,
+			 u_register_t x3,
+			 u_register_t x4,
 			 void *cookie,
 			 void *handle,
-			 uint64_t flags)
+			 u_register_t flags)
 {
 	/*
 	 * Dispatch OEM calls to OEM Common handler and return its return value