Allwinner sun4i USB PHY
-----------------------

Required properties:
- compatible : should be one of
  * allwinner,sun4i-a10-usb-phy
  * allwinner,sun5i-a13-usb-phy
  * allwinner,sun6i-a31-usb-phy
  * allwinner,sun7i-a20-usb-phy
  * allwinner,sun8i-a23-usb-phy
  * allwinner,sun8i-a33-usb-phy
  * allwinner,sun8i-h3-usb-phy
- reg : a list of offset + length pairs
- reg-names :
  * "phy_ctrl"
  * "pmu1"
  * "pmu2" for sun4i, sun6i or sun7i
- #phy-cells : from the generic phy bindings, must be 1
- clocks : phandle + clock specifier for the phy clocks
- clock-names :
  * "usb_phy" for sun4i, sun5i or sun7i
  * "usb0_phy", "usb1_phy" and "usb2_phy" for sun6i
  * "usb0_phy", "usb1_phy" for sun8i
- resets : a list of phandle + reset specifier pairs
- reset-names :
  * "usb0_reset"
  * "usb1_reset"
  * "usb2_reset" for sun4i, sun6i or sun7i

Optional properties:
- usb0_id_det-gpios : gpio phandle for reading the otg id pin value
- usb0_vbus_det-gpios : gpio phandle for detecting the presence of usb0 vbus
- usb0_vbus_power-supply: power-supply phandle for usb0 vbus presence detect
- usb0_vbus-supply : regulator phandle for controller usb0 vbus
- usb1_vbus-supply : regulator phandle for controller usb1 vbus
- usb2_vbus-supply : regulator phandle for controller usb2 vbus

Example:
	usbphy: phy@0x01c13400 {
		#phy-cells = <1>;
		compatible = "allwinner,sun4i-a10-usb-phy";
		/* phy base regs, phy1 pmu reg, phy2 pmu reg */
		reg = <0x01c13400 0x10 0x01c14800 0x4 0x01c1c800 0x4>;
		reg-names = "phy_ctrl", "pmu1", "pmu2";
		clocks = <&usb_clk 8>;
		clock-names = "usb_phy";
		resets = <&usb_clk 0>, <&usb_clk 1>, <&usb_clk 2>;
		reset-names = "usb0_reset", "usb1_reset", "usb2_reset";
		pinctrl-names = "default";
		pinctrl-0 = <&usb0_id_detect_pin>, <&usb0_vbus_detect_pin>;
		usb0_id_det-gpios = <&pio 7 19 GPIO_ACTIVE_HIGH>; /* PH19 */
		usb0_vbus_det-gpios = <&pio 7 22 GPIO_ACTIVE_HIGH>; /* PH22 */
		usb0_vbus-supply = <&reg_usb0_vbus>;
		usb1_vbus-supply = <&reg_usb1_vbus>;
		usb2_vbus-supply = <&reg_usb2_vbus>;
	};
