gpio: add GPIO controller driver for MediaTek MT7620 SoC

This patch adds GPIO controller driver for MediaTek MT7620 SoC

Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index d3d0d3c..8541ba0 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -64,6 +64,7 @@
 obj-$(CONFIG_MSM_GPIO)		+= msm_gpio.o
 obj-$(CONFIG_$(SPL_)PCF8575_GPIO)	+= pcf8575_gpio.o
 obj-$(CONFIG_PM8916_GPIO)	+= pm8916_gpio.o
+obj-$(CONFIG_MT7620_GPIO)	+= mt7620_gpio.o
 obj-$(CONFIG_MT7621_GPIO)	+= mt7621_gpio.o
 obj-$(CONFIG_MSCC_SGPIO)	+= mscc_sgpio.o
 obj-$(CONFIG_NX_GPIO)		+= nx_gpio.o