USB: qcserial: adding Sierra Wireless devices

The QMI mode of the Sierra Wireless MC7710 is close to
a Gobi device, and also identified as one by the
Windows drivers provided by Sony.  The serial interfaces
are the same as for any other Gobi module, but the USB
interface layout is different:

 0: DM/DIAG (also present in bootloader mode)
 2: NMEA
 3: AT-capable modem port
 8: QMI/net
 19: QMI/net (not always present)
 20: QMI/net (not always present)

Note in particular that the NMEA and AT ports are reversed
compared to a Gobi 2k+ device, and that the DM port appears
as a QDL port in bootloader mode using the same device ID.

The Sony driver also document two new devices with standard
Gobi 2k+ layout (1199:68a5, 1199:68a9) having a QDL mode
(1199:68a4, 1199:68a8).  Adding these as well.

Lenovo Windows drivers document the USB interface layout
for a few additional Sierra Wireless devices. Adding these
while at it:
- MC7770 (1199:901b) with standard Gobi 2k+ layout
- MC7700 (0f3d:68a2) with the same layout as MC7710
- MC7750 (114f:68a2) with the same layout as MC7710
- EM7700 (1199:901c) with the same layout as MC7710

Cc: Anton Samokhvalov <pg83@yandex.ru>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>