USB NOP PHY

Required properties:
- compatible: should be usb-nop-xceiv

Optional properties:
- clocks: phandle to the PHY clock. Use as per Documentation/devicetree
  /bindings/clock/clock-bindings.txt
  This property is required if clock-frequency is specified.

- clock-names: Should be "main_clk"

- clock-frequency: the clock frequency (in Hz) that the PHY clock must
  be configured to.

- vcc-supply: phandle to the regulator that provides power to the PHY.

- reset-gpios: Should specify the GPIO for reset.

- vbus-detect-gpio: should specify the GPIO detecting a VBus insertion
                    (see Documentation/devicetree/bindings/gpio/gpio.txt)
- vbus-regulator : should specifiy the regulator supplying current drawn from
  the VBus line (see Documentation/devicetree/bindings/regulator/regulator.txt).

Example:

	hsusb1_phy {
		compatible = "usb-nop-xceiv";
		clock-frequency = <19200000>;
		clocks = <&osc 0>;
		clock-names = "main_clk";
		vcc-supply = <&hsusb1_vcc_regulator>;
		reset-gpios = <&gpio1 7 GPIO_ACTIVE_LOW>;
		vbus-detect-gpio = <&gpio2 13 GPIO_ACTIVE_HIGH>;
		vbus-regulator = <&vbus_regulator>;
	};

hsusb1_phy is a NOP USB PHY device that gets its clock from an oscillator
and expects that clock to be configured to 19.2MHz by the NOP PHY driver.
hsusb1_vcc_regulator provides power to the PHY and GPIO 7 controls RESET.
GPIO 13 detects VBus insertion, and accordingly notifies the vbus-regulator.
