- CS46xx driver - removed unused variable
  - USB code
    - pass struct usb_interface pointer to the usb-midi parser.
      in usb-midi functions, this instance is used instead of parsing
      the interface from dev and ifnum.
    - allocate the descriptor buffer only for parsing the audio device.
    - clean up, new probe/disconnect callbacks for 2.4 API.
    - added the support for Yamaha and Midiman devices.