mediatek: mt8192: Add SiP service

Add the basic SiP service

Change-Id: Ib7f2380aab910adf8d33498a79ecd287273907c5
diff --git a/plat/mediatek/mt8192/include/plat_sip_calls.h b/plat/mediatek/mt8192/include/plat_sip_calls.h
new file mode 100644
index 0000000..0e42322
--- /dev/null
+++ b/plat/mediatek/mt8192/include/plat_sip_calls.h
@@ -0,0 +1,15 @@
+/*
+ * Copyright (c) 2020, MediaTek Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef PLAT_SIP_CALLS_H
+#define PLAT_SIP_CALLS_H
+
+/*******************************************************************************
+ * Plat SiP function constants
+ ******************************************************************************/
+#define MTK_PLAT_SIP_NUM_CALLS    0
+
+#endif /* PLAT_SIP_CALLS_H */