feat(mediatek): add SiP service for OP-TEE

Add SiP service for the SMC call from the secure world.

Change-Id: I7a5cfaac5c46ea65be793c3d291e4332cc0b2e54
diff --git a/plat/mediatek/include/mtk_sip_svc.h b/plat/mediatek/include/mtk_sip_svc.h
index ce51048..f677915 100644
--- a/plat/mediatek/include/mtk_sip_svc.h
+++ b/plat/mediatek/include/mtk_sip_svc.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
  */
@@ -55,11 +55,13 @@
 
 MTK_SIP_SMC_FROM_BL33_TABLE(SMC_ID_EXPAND_AS_EXTERN_SMC_INDEX);
 MTK_SIP_SMC_FROM_NS_EL1_TABLE(SMC_ID_EXPAND_AS_EXTERN_SMC_INDEX);
+MTK_SIP_SMC_FROM_S_EL1_TABLE(SMC_ID_EXPAND_AS_EXTERN_SMC_INDEX);
 
 /* Expand SiP SMC ID table as enum */
 enum {
 	MTK_SIP_SMC_FROM_BL33_TABLE(SMC_ID_EXPAND_AS_ENUM)
 	MTK_SIP_SMC_FROM_NS_EL1_TABLE(SMC_ID_EXPAND_AS_ENUM)
+	MTK_SIP_SMC_FROM_S_EL1_TABLE(SMC_ID_EXPAND_AS_ENUM)
 	MTK_SIP_SMC_MAX_NUMBER
 };