feat(mt8188): add emi mpu protection for APU secure memory

Add emi mpu protection of APU secure memory.

Change-Id: I949cfce97565d8a313caae4ea41af60a171042a6
diff --git a/plat/mediatek/drivers/emi_mpu/emi_mpu.h b/plat/mediatek/drivers/emi_mpu/emi_mpu.h
index 66a369e..9c1ebb5 100644
--- a/plat/mediatek/drivers/emi_mpu/emi_mpu.h
+++ b/plat/mediatek/drivers/emi_mpu/emi_mpu.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2022-2023, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -60,5 +60,6 @@
 int emi_mpu_init(void);
 int emi_mpu_set_protection(struct emi_region_info_t *region_info);
 void set_emi_mpu_regions(void);
+int set_apu_emi_mpu_region(void);
 
 #endif