ARM: shmobile: r8a7790: link PCI USB devices to USB PHY

Describe the PCI USB devices that are behind the PCI bridges, adding necessary
links to the USB PHY device.

Based on the original work by Ben Dooks <ben.dooks@codethink.co.uk>.
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/boot/dts/r8a7790.dtsi

@@ -1197,6 +1197,20 @@ pci0: pci@ee090000 {
 		interrupt-map = <0x0000 0 0 1 &gic 0 108 IRQ_TYPE_LEVEL_HIGH
 				 0x0800 0 0 1 &gic 0 108 IRQ_TYPE_LEVEL_HIGH
 				 0x1000 0 0 2 &gic 0 108 IRQ_TYPE_LEVEL_HIGH>;
+
+		usb@0,1 {
+			reg = <0x800 0 0 0 0>;
+			device_type = "pci";
+			phys = <&usb0 0>;
+			phy-names = "usb";
+		};
+
+		usb@0,2 {
+			reg = <0x1000 0 0 0 0>;
+			device_type = "pci";
+			phys = <&usb0 0>;
+			phy-names = "usb";
+		};
 	};
 
 	pci1: pci@ee0b0000 {
@@ -1237,6 +1251,20 @@ pci2: pci@ee0d0000 {
 		interrupt-map = <0x0000 0 0 1 &gic 0 113 IRQ_TYPE_LEVEL_HIGH
 				 0x0800 0 0 1 &gic 0 113 IRQ_TYPE_LEVEL_HIGH
 				 0x1000 0 0 2 &gic 0 113 IRQ_TYPE_LEVEL_HIGH>;
+
+		usb@0,1 {
+			reg = <0x800 0 0 0 0>;
+			device_type = "pci";
+			phys = <&usb2 0>;
+			phy-names = "usb";
+		};
+
+		usb@0,2 {
+			reg = <0x1000 0 0 0 0>;
+			device_type = "pci";
+			phys = <&usb2 0>;
+			phy-names = "usb";
+		};
 	};
 
 	pciec: pcie@fe000000 {