usb: cdc_acm: Add quirk for Castles VEGA3000

The device (a POS terminal) implements CDC ACM, but has not union
descriptor.
Signed-off-by: NLubomir Rintel <lkundrak@v3.sk>
Acked-by: NOliver Neukum <oneukum@suse.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/class/cdc-acm.c

@@ -1831,6 +1831,9 @@ static const struct usb_device_id acm_ids[] = {
 	{ USB_DEVICE(0x09d8, 0x0320), /* Elatec GmbH TWN3 */
 	.driver_info = NO_UNION_NORMAL, /* has misplaced union descriptor */
 	},
+	{ USB_DEVICE(0x0ca6, 0xa050), /* Castles VEGA3000 */
+	.driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */
+	},
 
 	{ USB_DEVICE(0x2912, 0x0001), /* ATOL FPrint */
 	.driver_info = CLEAR_HALT_CONDITIONS,