BROADCOM NORTHSTAR2 USB2 (DUAL ROLE DEVICE) PHY

Required properties:
 - compatible: brcm,ns2-drd-phy
 - reg: offset and length of the NS2 PHY related registers.
 - reg-names
   The below registers must be provided.
   icfg - for DRD ICFG configurations
   rst-ctrl - for DRD IDM reset
   crmu-ctrl - for CRMU core vdd, PHY and PHY PLL reset
   usb2-strap - for port over current polarity reversal
 - #phy-cells: Must be 0. No args required.
 - vbus-gpios: vbus gpio binding
 - id-gpios: id gpio binding

Refer to phy/phy-bindings.txt for the generic PHY binding properties

Example:
	usbdrd_phy: phy@66000960 {
			#phy-cells = <0>;
			compatible = "brcm,ns2-drd-phy";
			reg = <0x66000960 0x24>,
			      <0x67012800 0x4>,
			      <0x6501d148 0x4>,
			      <0x664d0700 0x4>;
			reg-names = "icfg", "rst-ctrl",
				    "crmu-ctrl", "usb2-strap";
			id-gpios = <&gpio_g 30 0>;
			vbus-gpios = <&gpio_g 31 0>;
	};
