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.h b/plat/mediatek/common/mtk_plat_common.h
index 7513bc7..501c339 100644
--- a/plat/mediatek/common/mtk_plat_common.h
+++ b/plat/mediatek/common/mtk_plat_common.h
@@ -48,10 +48,10 @@
 /* Declarations for mtk_plat_common.c */
 uint32_t plat_get_spsr_for_bl32_entry(void);
 uint32_t plat_get_spsr_for_bl33_entry(void);
-void clean_top_32b_of_param(uint32_t smc_fid, uint64_t *x1,
-				uint64_t *x2,
-				uint64_t *x3,
-				uint64_t *x4);
+void clean_top_32b_of_param(uint32_t smc_fid, u_register_t *x1,
+				u_register_t *x2,
+				u_register_t *x3,
+				u_register_t *x4);
 void bl31_prepare_kernel_entry(uint64_t k32_64);
 void enable_ns_access_to_cpuectlr(void);
 void boot_to_kernel(uint64_t x1, uint64_t x2, uint64_t x3, uint64_t x4);