USB: sierra: add support for Sierra Wireless MC7710

Just add new device id. 3G works fine, LTE not tested.
Signed-off-by: NAnton Samokhvalov <pg83@yandex.ru>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/serial/sierra.c

@@ -289,6 +289,7 @@ static const struct usb_device_id id_table[] = {
 	{ USB_DEVICE(0x1199, 0x6856) },	/* Sierra Wireless AirCard 881 U */
 	{ USB_DEVICE(0x1199, 0x6859) },	/* Sierra Wireless AirCard 885 E */
 	{ USB_DEVICE(0x1199, 0x685A) },	/* Sierra Wireless AirCard 885 E */
+	{ USB_DEVICE(0x1199, 0x68A2) }, /* Sierra Wireless MC7710 */
 	/* Sierra Wireless C885 */
 	{ USB_DEVICE_AND_INTERFACE_INFO(0x1199, 0x6880, 0xFF, 0xFF, 0xFF)},
 	/* Sierra Wireless C888, Air Card 501, USB 303, USB 304 */