usb: dwc3-uniphier: Select PHY

Make sure the PHY subsystem is activated for the uniphier DWC3 glue
logic, as it depends on PHY implementation there.

Signed-off-by: Marek Vasut <marex@denx.de>
diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index 7ddfa94..d1665f8 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -57,6 +57,7 @@
 	bool "DesignWare USB3 Host Support on UniPhier Platforms"
 	depends on ARCH_UNIPHIER && USB_DWC3
 	select USB_DWC3_GENERIC
+	select PHY
 	select PHY_UNIPHIER_USB3
 	help
 	  Support of USB2/3 functionality in Socionext UniPhier platforms.