pinctrl: mediatek: add pinctrl driver for MT7988 SoC

This patch adds pinctrl and gpio support for MT7988 SoC

diff --git a/drivers/pinctrl/mediatek/Makefile b/drivers/pinctrl/mediatek/Makefile
index 6e73375..de39d1e 100644
--- a/drivers/pinctrl/mediatek/Makefile
+++ b/drivers/pinctrl/mediatek/Makefile
@@ -8,6 +8,7 @@
 obj-$(CONFIG_PINCTRL_MT7629) += pinctrl-mt7629.o
 obj-$(CONFIG_PINCTRL_MT7981) += pinctrl-mt7981.o
 obj-$(CONFIG_PINCTRL_MT7986) += pinctrl-mt7986.o
+obj-$(CONFIG_PINCTRL_MT7988) += pinctrl-mt7988.o
 obj-$(CONFIG_PINCTRL_MT8512) += pinctrl-mt8512.o
 obj-$(CONFIG_PINCTRL_MT8516) += pinctrl-mt8516.o
 obj-$(CONFIG_PINCTRL_MT8518) += pinctrl-mt8518.o