lsusb: add VideoControl Endpoint Descriptor.

[tsundre]

Add support for parsing the Class-specific VC Interrupt Endpoint Descriptor as described in UVC 1.1 spec 3.8.2.2.

Sample output, including the preceding endpoint descriptor:

      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0010  1x 16 bytes
        bInterval               8
        bMaxBurst               0
        VideoControl Endpoint Descriptor:
          bLength                 5
          bDescriptorType        37
          bDescriptorSubtype      3 (EP_INTERRUPT)
          wMaxTransferSize       16