Tegra SOC XHCI controller

The device node for the Tegra XHCI host controller.

Required properties:
 - compatible: Should be "nvidia,tegra114-xhci" or "nvidia,tegra124-xhci" for
   XHCI controllers used in host mode.
 - reg: Address and length of the register sets.  There should be three
   entries in the following order: XHCI host registers, FPCI registers, and
   IPFS registers.
 - interrupts: Interrupts used by the controller.  There should be two
   entries in the following order: XHCI host interrupt and firmware mailbox
   interrupt.
 - clocks: Handles to XUSB host, falcon, and EMC clocks.
 - clock-names: Should be "xusb_host", "xusb_falcon_src", and "xusb.emc"
   respectively.
 - nvidia,xusb-phy: Handle to the corresponding XUSB PHY.
 - s1p05v-supply: 1.05V supply regulator.
 - s1p8v-supply: 1.8V supply regulator.
 - s3p3v-supply: 3.3V supply regulator.

Example:
	usb@70090000 {
		compatible = "nvidia,tegra124-xhci";
		reg = <0x0 0x70090000 0x8000>,
		      <0x0 0x70098000 0x1000>,
		      <0x0 0x70099000 0x1000>;
		interrupts = <GIC_SPI 39 IRQ_TYPE_LEVEL_HIGH>,
			     <GIC_SPI 40 IRQ_TYPE_LEVEL_HIGH>;
		clocks = <&tegra_car TEGRA124_CLK_XUSB_HOST>,
			 <&tegra_car TEGRA124_CLK_XUSB_FALCON_SRC>,
			 <&tegra_car TEGRA124_CLK_XUSB_EMC>;
		clock-names = "xusb_host", "xusb_falcon_src", "xusb.emc";
		nvidia,xusb-phy = <&xusb_phy>;
		s3p3v-supply = <&_3v3_lp0>;
		s1p8v-supply = <&vddio_1v8>;
		s1p05v-supply = <&avdd_hdmi_pex>;
		status = "okay";
	};