Device tree binding documentation for Motorola Mapphone MDM6600 USB PHY

Required properties:
- compatible		Must be "motorola,mapphone-mdm6600"
- enable-gpios		GPIO to enable the USB PHY
- power-gpios		GPIO to power on the device
- reset-gpios		GPIO to reset the device
- motorola,mode-gpios	Two GPIOs to configure MDM6600 USB start-up mode for
			normal mode versus USB flashing mode
- motorola,cmd-gpios	Three GPIOs to control the power state of the MDM6600
- motorola,status-gpios	Three GPIOs to read the power state of the MDM6600

Example:

usb-phy {
	compatible = "motorola,mapphone-mdm6600";
	enable-gpios = <&gpio3 31 GPIO_ACTIVE_LOW>;
	power-gpios = <&gpio2 22 GPIO_ACTIVE_HIGH>;
	reset-gpios = <&gpio2 17 GPIO_ACTIVE_HIGH>;
	motorola,mode-gpios = <&gpio5 20 GPIO_ACTIVE_HIGH>,
			      <&gpio5 21 GPIO_ACTIVE_HIGH>;
	motorola,cmd-gpios = <&gpio4 7 GPIO_ACTIVE_HIGH>,
			     <&gpio4 8 GPIO_ACTIVE_HIGH>,
			     <&gpio5 14 GPIO_ACTIVE_HIGH>;
	motorola,status-gpios = <&gpio2 20 GPIO_ACTIVE_HIGH>,
				<&gpio2 21 GPIO_ACTIVE_HIGH>,
				<&gpio2 23 GPIO_ACTIVE_HIGH>;
	#phy-cells = <0>;
};
