feat(mt8188): add pinctrl support

Add pinctrl support for MT8188.

TEST=build pass
BUG=b:236331724

Signed-off-by: Jianguo Zhang <jianguo.zhang@mediatek.corp-partner.google.com>
Change-Id: Id4ac8f67009621fff8f15f3ab2d8f200343c8356
diff --git a/plat/mediatek/drivers/gpio/rules.mk b/plat/mediatek/drivers/gpio/rules.mk
new file mode 100644
index 0000000..78061a8
--- /dev/null
+++ b/plat/mediatek/drivers/gpio/rules.mk
@@ -0,0 +1,18 @@
+#
+# Copyright (c) 2022, MediaTek Inc. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+LOCAL_DIR := $(call GET_LOCAL_DIR)
+
+MODULE := gpio
+
+LOCAL_SRCS-y := drivers/gpio/gpio.c
+LOCAL_SRCS-y += ${LOCAL_DIR}/mtgpio_common.c
+LOCAL_SRCS-y += ${LOCAL_DIR}/${MTK_SOC}/mtgpio.c
+
+PLAT_INCLUDES += -I${LOCAL_DIR}
+PLAT_INCLUDES += -I${LOCAL_DIR}/${MTK_SOC}
+
+$(eval $(call MAKE_MODULE,$(MODULE),$(LOCAL_SRCS-y),$(MTK_BL)))