mediatek: mt8192: Add MCDI drivers

Add MCDI related drivers to handle CPU powered on/off in CPU suspend.

Change-Id: I5110461e8eef86f8383b45f197ec5cb10dbfeb3e
diff --git a/plat/mediatek/mt8192/drivers/mcdi/mt_mcdi.h b/plat/mediatek/mt8192/drivers/mcdi/mt_mcdi.h
new file mode 100644
index 0000000..f3545aa
--- /dev/null
+++ b/plat/mediatek/mt8192/drivers/mcdi/mt_mcdi.h
@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2020, MediaTek Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef MT_MCDI_H
+#define MT_MCDI_H
+
+int mcdi_try_init(void);
+
+#endif /* MT_MCDI_H */