ARM: shmobile: r8a7794: add USB PHY DT support

Define the R8A7794 generic part of the USB PHY device node. It is up to the
board file to enable the device.
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7794.dtsi

@@ -690,6 +690,26 @@
 				 0x1000 0 0 2 &gic 0 113 IRQ_TYPE_LEVEL_HIGH>;
 	};
 
+	usbphy: usb-phy@e6590100 {
+		compatible = "renesas,usb-phy-r8a7794";
+		reg = <0 0xe6590100 0 0x100>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		clocks = <&mstp7_clks R8A7794_CLK_HSUSB>;
+		clock-names = "usbhs";
+		power-domains = <&cpg_clocks>;
+		status = "disabled";
+
+		usb0: usb-channel@0 {
+			reg = <0>;
+			#phy-cells = <1>;
+		};
+		usb2: usb-channel@2 {
+			reg = <2>;
+			#phy-cells = <1>;
+		};
+	};
+
 	clocks {
 		#address-cells = <2>;
 		#size-cells = <2>;