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
Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: David S. Miller <davem@davemloft.net>