pinctrl: mediatek: add pinctrl driver for MT7988 SoC

This patch adds pinctrl and gpio support for MT7988 SoC

diff --git a/drivers/pinctrl/mediatek/Kconfig b/drivers/pinctrl/mediatek/Kconfig
index 27e8998..34d23ce 100644
--- a/drivers/pinctrl/mediatek/Kconfig
+++ b/drivers/pinctrl/mediatek/Kconfig
@@ -24,6 +24,10 @@
 	bool "MT7986 SoC pinctrl driver"
 	select PINCTRL_MTK
 
+config PINCTRL_MT7988
+	bool "MT7988 SoC pinctrl driver"
+	select PINCTRL_MTK
+
 config PINCTRL_MT8512
 	bool "MT8512 SoC pinctrl driver"
 	select PINCTRL_MTK