USB: Sierra - Add support for Aircard 881U

Adds the appropriate vendor and device IDs for the AirCard 881U to
sierra.c. (This device is often rebadged by AT&T as the USBConnect 881).

Cc: stable <stable@kernel.org>
Signed-off-by: NJessica L Blank <j@twu.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/serial/sierra.c

@@ -117,6 +117,7 @@ static struct usb_device_id id_table [] = {
 	{ USB_DEVICE(0x1199, 0x6851) },	/* Sierra Wireless AirCard 881 */
 	{ USB_DEVICE(0x1199, 0x6852) },	/* Sierra Wireless AirCard 880 E */
 	{ USB_DEVICE(0x1199, 0x6853) },	/* Sierra Wireless AirCard 881 E */
+	{ USB_DEVICE(0x1199, 0x6856) },	/* Sierra Wireless AirCard 881 U */
 
 	{ USB_DEVICE(0x1199, 0x0112), .driver_info = DEVICE_1_PORT }, /* Sierra Wireless AirCard 580 */
 	{ USB_DEVICE(0x0F3D, 0x0112), .driver_info = DEVICE_1_PORT }, /* Airprime/Sierra PC 5220 */
@@ -155,6 +156,7 @@ static struct usb_device_id id_table_3port [] = {
 	{ USB_DEVICE(0x1199, 0x6851) },	/* Sierra Wireless AirCard 881 */
 	{ USB_DEVICE(0x1199, 0x6852) },	/* Sierra Wireless AirCard 880E */
 	{ USB_DEVICE(0x1199, 0x6853) },	/* Sierra Wireless AirCard 881E */
+	{ USB_DEVICE(0x1199, 0x6856) },	/* Sierra Wireless AirCard 881U */
 	{ }
 };