pinctrl: mtmips: add support for MediaTek MT7620 SoC

This patch adds pinctrl support for MediaTek MT7620 SoC.
The MT7620 SoC supports only pinmux.

Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/drivers/pinctrl/mtmips/Makefile b/drivers/pinctrl/mtmips/Makefile
index 3ba5c0c..ba945a8 100644
--- a/drivers/pinctrl/mtmips/Makefile
+++ b/drivers/pinctrl/mtmips/Makefile
@@ -4,4 +4,5 @@
 obj-$(CONFIG_PINCTRL_MTMIPS) += pinctrl-mtmips-common.o
 
 # SoC Drivers
+obj-$(CONFIG_PINCTRL_MT7620) += pinctrl-mt7620.o
 obj-$(CONFIG_PINCTRL_MT7628) += pinctrl-mt7628.o