Usually, we only use device tree for hard wired USB device.
The reference binding doc is from:
-http://www.firmware.org/1275/bindings/usb/usb-1_0.ps
+http://www.devicetree.org/open-firmware/bindings/usb/usb-1_0.ps
Required properties:
- compatible: usbVID,PID. The textual representation of VID, PID shall