feat(mt8188): add DFD control in SiP service

DFD (Design for Debug) is a debugging tool, which scans flip-flops and
dumps to internal RAM on the WDT reset. After system reboots, those
values could be showed for debugging.

TEST=build pass.
BUG=b:244216434

Signed-off-by: Fengquan Chen <fengquan.chen@mediatek.corp-partner.google.com>
Change-Id: I468036131e941a46bc1ec12d33105146000730d8
diff --git a/plat/mediatek/drivers/dfd/dfd.h b/plat/mediatek/drivers/dfd/dfd.h
new file mode 100644
index 0000000..c088bd0
--- /dev/null
+++ b/plat/mediatek/drivers/dfd/dfd.h
@@ -0,0 +1,16 @@
+/*
+ * Copyright (c) 2022, MediaTek Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef DFD_H
+#define DFD_H
+
+#include <arch_helpers.h>
+#include <lib/mmio.h>
+
+void dfd_resume(void);
+void dfd_setup(uint64_t base_addr, uint64_t chain_length, uint64_t cache_dump);
+
+#endif /* DFD_H */