ARM: shmobile: silk: enable USB PHY

Enable USB PHY device for the SILK board.
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7794-silk.dts

@@ -210,3 +210,7 @@
 	pinctrl-0 = <&usb1_pins>;
 	pinctrl-names = "default";
 };
+
+&usbphy {
+	status = "okay";
+};