Tegra SOC USB PHY

The device node for Tegra SOC USB PHY:

Required properties :
 - compatible : Should be "nvidia,tegra20-usb-phy".
 - reg : Address and length of the register set for the USB PHY interface.
 - phy_type : Should be one of "ulpi" or "utmi".

Required properties for phy_type == ulpi:
  - nvidia,phy-reset-gpio : The GPIO used to reset the PHY.

Optional properties:
  - nvidia,has-legacy-mode : boolean indicates whether this controller can
    operate in legacy mode (as APX 2500 / 2600). In legacy mode some
    registers are accessed through the APB_MISC base address instead of
    the USB controller.