ANDROID USB:

This describes the device tree node for the Android USB gadget device.
This works in conjunction with a USB Device Controller (UDC) to provide
a dynamically configurable composition of functions to be exposed when
connected to a USB host.

Required properties:
- compatible: should be "qcom,android-usb"

Optional properties :
- reg  : offset and length of memory region that is used by device to
  update USB PID and serial numbers used by bootloader in DLOAD mode.
- qcom,pm-qos-latency : This property must be a list of three integer values
  (perf, normal, sleep) where each value respresents DMA latency in microsecs.
  First value represents DMA latency to vote with pm_qos when back to back USB
  transfers are happening and it requires USB thoughput to be maximum.
  Second value represents value to vote when not many USB transfers are
  happening and it is OK to have higher DMA latency to save power.
  Third value represents DMA latency to vote when USB BUS is IDLE and absolutely
  no transfers are happening. It should allow transition to lowest power state.
- qcom,usb-core-id: Index to refer USB hardware core to bind android gadget driver
  with UDC if multiple USB peripheral controllers are present. If unspecified,
  core is set to zero by default.
- qcom,supported-func: Represents list of supported function drivers. If this
  property is present android USB driver dynamically creats the list of
  supported function drivers and uses this list instead of statically defined default
  supported function driver list.
Example Android USB device node :
	android_usb@fc42b0c8 {
		compatible = "qcom,android-usb";
		reg = <0xfc42b0c8 0xc8>;
		qcom,pm-qos-latency = <2 1001 12701>;
		qcom,supported-func = "rndis_gsi","ecm_gsi","rmnet_gsi";
		qcom,usb-core-id = <1>;
	};