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/mtk_plat_common.c b/plat/mediatek/common/mtk_plat_common.c
index 6a13192..a15131d 100644
--- a/plat/mediatek/common/mtk_plat_common.c
+++ b/plat/mediatek/common/mtk_plat_common.c
@@ -19,10 +19,10 @@
 struct atf_arg_t gteearg;
 
 void clean_top_32b_of_param(uint32_t smc_fid,
-				uint64_t *px1,
-				uint64_t *px2,
-				uint64_t *px3,
-				uint64_t *px4)
+				u_register_t *px1,
+				u_register_t *px2,
+				u_register_t *px3,
+				u_register_t *px4)
 {
 	/* if parameters from SMC32. Clean top 32 bits */
 	if (0 == (smc_fid & SMC_AARCH64_BIT)) {