feat(mt8188): add support for SMC from OP-TEE

- Add MTK_SIP_SMC_FROM_S_EL1_TABLE to handle the SMC call from OP-TEE.
- Register optee for EMI MPU.

Change-Id: Ie94542f0e3966c4c25f2b7233b9355d41f8f36a5
diff --git a/plat/mediatek/drivers/emi_mpu/emi_mpu_common.c b/plat/mediatek/drivers/emi_mpu/emi_mpu_common.c
index bf77791..7eeadec 100644
--- a/plat/mediatek/drivers/emi_mpu/emi_mpu_common.c
+++ b/plat/mediatek/drivers/emi_mpu/emi_mpu_common.c
@@ -7,6 +7,8 @@
 #include <string.h>
 #include <common/debug.h>
 #include <lib/mmio.h>
+#include <smccc_helpers.h>
+
 #include <emi_mpu.h>
 #include <lib/mtk_init/mtk_init.h>
 #include <mtk_sip_svc.h>
@@ -116,7 +118,10 @@
 				     u_register_t x3, u_register_t x4,
 				     void *handle, struct smccc_res *smccc_ret)
 {
-	/* TODO: implement emi mpu handler */
+	int ret;
+
+	ret = emi_mpu_optee_handler(x1, x2, x3);
+	SMC_RET2(handle, ret, 0U);
 
 	return 0;
 }