Elatec TWN3 has the union descriptor on data interface. This results in
failure to bind the device to the driver with the following log:
  usb 1-1.2: new full speed USB device using streamplug-ehci and address 4
  usb 1-1.2: New USB device found, idVendor=09d8, idProduct=0320
  usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
  usb 1-1.2: Product: RFID Device (COM)
  usb 1-1.2: Manufacturer: OEM
  cdc_acm 1-1.2:1.0: Zero length descriptor references
  cdc_acm: probe of 1-1.2:1.0 failed with error -22

Adding the NO_UNION_NORMAL quirk for the device fixes the issue.

`lsusb -v` of the device:

Bus 001 Device 003: ID 09d8:0320
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            2 Communications
  bDeviceSubClass         0
  bDeviceProtocol         0
  bMaxPacketSize0        32
  idVendor           0x09d8
  idProduct          0x0320
  bcdDevice            3.00
  iManufacturer           1 OEM
  iProduct                2 RFID Device (COM)
  iSerial                 0
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           67
    bNumInterfaces          2
    bConfigurationValue     1
    iConfiguration          0
    bmAttributes         0x80
      (Bus Powered)
    MaxPower              250mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         2 Communications
      bInterfaceSubClass      2 Abstract (modem)
      bInterfaceProtocol      1 AT-commands (v.25ter)
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x83  EP 3 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0020  1x 32 bytes
        bInterval               2
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass        10 CDC Data
      bInterfaceSubClass      0 Unused
      bInterfaceProtocol      0
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x02  EP 2 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0020  1x 32 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0020  1x 32 bytes
        bInterval               0
      CDC Header:
        bcdCDC               1.10
      CDC Call Management:
        bmCapabilities       0x03
          call management
          use DataInterface
        bDataInterface          1
      CDC ACM:
        bmCapabilities       0x06
          sends break
          line coding and serial state
      CDC Union:
        bMasterInterface        0
        bSlaveInterface         1
Device Status:     0x0000
  (Bus Powered)
Signed-off-by: Maksim Salau <msalau@iotecha.com>
Acked-by: Oliver Neukum <oneukum@suse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>