feat(mt8186): add SPM suspend driver

Add SPM suspend driver for suspend/resume features.

TEST=build pass
BUG=b:202871018

Change-Id: I25b4b97cd3138a7b347385539e47ccfa884d64fc
diff --git a/plat/mediatek/mt8186/aarch64/platform_common.c b/plat/mediatek/mt8186/aarch64/platform_common.c
index 9b9697f..021cab7 100644
--- a/plat/mediatek/mt8186/aarch64/platform_common.c
+++ b/plat/mediatek/mt8186/aarch64/platform_common.c
@@ -15,6 +15,8 @@
 			MT_DEVICE | MT_RW | MT_SECURE),
 	MAP_REGION_FLAT(MTK_DEV_RNG2_BASE, MTK_DEV_RNG2_SIZE,
 			MT_DEVICE | MT_RW | MT_SECURE),
+	MAP_REGION_FLAT(MTK_MCDI_SRAM_BASE, MTK_MCDI_SRAM_MAP_SIZE,
+			MT_DEVICE | MT_RW | MT_SECURE),
 	{ 0 }
 };