phy: add USB PHY driver for MediaTek MT7620 SoC

This patch adds USB PHY driver for MediaTek MT7620 SoC

Reviewed-by: Stefan Roese <sr@denx.de>
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index 45a7fe5..6b3761b 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -24,6 +24,7 @@
 obj-$(CONFIG_MSM8916_USB_PHY) += msm8916-usbh-phy.o
 obj-$(CONFIG_OMAP_USB2_PHY) += omap-usb2-phy.o
 obj-$(CONFIG_KEYSTONE_USB_PHY) += keystone-usb-phy.o
+obj-$(CONFIG_MT7620_USB_PHY) += mt7620-usb-phy.o
 obj-$(CONFIG_MT76X8_USB_PHY) += mt76x8-usb-phy.o
 obj-$(CONFIG_PHY_DA8XX_USB) += phy-da8xx-usb.o
 obj-$(CONFIG_PHY_MTK_TPHY) += phy-mtk-tphy.o