feat(plat/mediatek/mt8195): add SPM suspend driver

Support DRAM/MAINPLL/26M off when system suspend.

Signed-off-by: Edward-JW Yang <edward-jw.yang@mediatek.corp-partner.google.com>
Change-Id: Ib8502f9b0b4e47aa405e5449f0b6d483bd3f5d77
diff --git a/plat/mediatek/mt8195/drivers/spm/mt_spm_idle.h b/plat/mediatek/mt8195/drivers/spm/mt_spm_idle.h
new file mode 100644
index 0000000..7f6fb0c
--- /dev/null
+++ b/plat/mediatek/mt8195/drivers/spm/mt_spm_idle.h
@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2021, MediaTek Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef MT_SPM_IDLE_H
+#define MT_SPM_IDLE_H
+
+typedef void (*spm_idle_conduct)(struct spm_lp_scen *spm_lp,
+				 unsigned int *resource_req);
+int mt_spm_idle_generic_enter(int state_id, unsigned int ext_opand,
+			      spm_idle_conduct fn);
+void mt_spm_idle_generic_resume(int state_id, unsigned int ext_opand,
+				struct wake_status **status);
+void mt_spm_idle_generic_init(void);
+#endif /* MT_SPM_IDLE_H */