feat(plat/mediatek/mt8195): support MCUSYS off when system suspend

Add drivers to support MCUSYS off when system suspend.

Signed-off-by: Edward-JW Yang <edward-jw.yang@mediatek.corp-partner.google.com>
Change-Id: I388fd2318f471083158992464ecdf2181fc7d87a
diff --git a/plat/mediatek/mt8195/drivers/mcdi/mt_mcdi.c b/plat/mediatek/mt8195/drivers/mcdi/mt_mcdi.c
index df74122..c14e83b 100644
--- a/plat/mediatek/mt8195/drivers/mcdi/mt_mcdi.c
+++ b/plat/mediatek/mt8195/drivers/mcdi/mt_mcdi.c
@@ -1,10 +1,11 @@
 /*
- * Copyright (c) 2020, MediaTek Inc. All rights reserved.
+ * Copyright (c) 2021, MediaTek Inc. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
 #include <cdefs.h>
+#include <common/debug.h>
 
 #include <lib/mmio.h>
 #include <lib/utils_def.h>
@@ -144,5 +145,7 @@
 		mcdi_init_status = MCDI_INIT_DONE;
 	}
 
+	INFO("mcdi ready for mcusys-off-idle and system suspend\n");
+
 	return (mcdi_init_status == MCDI_INIT_DONE) ? 0 : mcdi_init_status;
 }