Marvell SOC USB controllers

This controller is integrated in Armada 3700/8K.
It uses the same properties as a generic XHCI host controller

Required properties :
 - compatible: should be one or more of:
   - "marvell,armada3700-xhci", "generic-xhci" for Armada 37xx SoCs
   - "marvell,armada-8k-xhci", "generic-xhci" for Armada A8K SoCs
 - reg: should contain address and length of the standard XHCI
   register set for the device.
 - interrupts: one XHCI interrupt should be described here.

Optional properties:
 - clocks: phandle to system controller clock driving this unit
 - vbus-supply : If present, specifies the fixed regulator to be turned on
   for providing power to the USB VBUS rail.

Example:
	cpm_usb3_0: usb3@500000 {
		compatible = "marvell,armada-8k-xhci",
			     "generic-xhci";
		reg = <0x500000 0x4000>;
		interrupts = <GIC_SPI 62 IRQ_TYPE_LEVEL_HIGH>;
		clocks = <&cpm_syscon0 1 22>;
		vbus-supply = <&reg_usb3h0_vbus>;
		status = "disabled";
	};
