usb: qcserial: add Netgear Aircard 340U

This device was mentioned in an OpenWRT forum.  Seems to have a "standard"
Sierra Wireless ifnumber to function layout:
 0: qcdm
 2: nmea
 3: modem
 8: qmi
 9: storage

Cc: <stable@vger.kernel.org>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>