feat(mediatek): introduce mtk init framework

Provide six initcall levels for drivers/modules initialize HW
controllers or runtime arguments during cold boot.

The initcall level cold boot execution order:

-MTK_EARLY_PLAT_INIT
Call before MMU enabled.

-MTK_ARCH_INIT
MMU Enabled, arch related init(GiC init, interrupt type registration).

-MTK_PLAT_SETUP_0_INIT
MTK driver init level 0.

-MTK_PLAT_SETUP_1_INIT
MTK driver init level 1.

-MTK_PLAT_RUNTIME_INIT
MTK driver init. After this initcall, TF-A handovers to MTK 2nd
bootloader.

-MTK_PLAT_BL33_DEFER_INIT
MTK 2nd bootloader traps to TF-A before handover to rich OS.
This initcall executed in the trap handler(boot_to_kernel).

Change-Id: Icd7fe95372441db73c975ccb6ce77a6c529df1cc
diff --git a/plat/mediatek/lib/mtk_init/mtk_init.c b/plat/mediatek/lib/mtk_init/mtk_init.c
new file mode 100644
index 0000000..2289659
--- /dev/null
+++ b/plat/mediatek/lib/mtk_init/mtk_init.c
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2022, MediaTek Inc. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <common/debug.h>
+#include <lib/utils_def.h>
+#include <lib/mtk_init/mtk_init.h>
+
+INIT_CALL_TABLE(EXPAND_AS_EXTERN);
+extern struct initcall __MTK_PLAT_INITCALL_END__[];
+
+struct initcall *initcall_list[] = {
+	INIT_CALL_TABLE(EXPAND_AS_SYMBOL_ARR)
+	__MTK_PLAT_INITCALL_END__
+};
+
+void mtk_init_one_level(uint32_t level)
+{
+	const struct initcall *entry;
+	int error;
+
+	if (level >= MTK_INIT_LVL_MAX) {
+		ERROR("invalid level:%u\n", level);
+		panic();
+	}
+
+	INFO("init calling level:%u\n", level);
+	for (entry = initcall_list[level];
+	     (entry != NULL) && (entry < initcall_list[level + 1]);
+	     entry++) {
+		INFO("calling %s\n", entry->name);
+		error = entry->fn();
+		if (error != 0) {
+			ERROR("init %s fail, errno:%d\n", entry->name, error);
+		}
+	}
+}