USB: serial: Add Option GTM681W to qcserial device table.

commit 8a2f132a01c2dd4c3905fa560f92019761ed72b1 upstream.

The Option GTM681W uses a qualcomm chip and can be
served by the qcserial device driver.

Signed-off-by: Richard Weinberger <richard@nod.at>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/serial/qcserial.c b/drivers/usb/serial/qcserial.c
index c7ccbc6..9280e74 100644
--- a/drivers/usb/serial/qcserial.c
+++ b/drivers/usb/serial/qcserial.c
@@ -121,6 +121,7 @@
 	{USB_DEVICE(0x1199, 0x9019)},	/* Sierra Wireless Gobi 3000 Modem device */
 	{USB_DEVICE(0x12D1, 0x14F0)},	/* Sony Gobi 3000 QDL */
 	{USB_DEVICE(0x12D1, 0x14F1)},	/* Sony Gobi 3000 Composite */
+	{USB_DEVICE(0x0AF0, 0x8120)},	/* Option GTM681W */
 	{ }				/* Terminating entry */
 };
 MODULE_DEVICE_TABLE(usb, id_table);