net: qmi_wwan: add Huawei E173

The Huawei E173 is a QMI/wwan device which normally appear
as 12d1:1436 in Linux. The descriptors displayed in that
mode will be picked up by cdc_ether.  But the modem has
another mode with a different device ID and a slightly
different set of descriptors. This is the mode used by
Windows like this:

3Modem:      USB\VID_12D1&PID_140C&MI_00\6&3A1D2012&0&0000
Networkcard: USB\VID_12D1&PID_140C&MI_01\6&3A1D2012&0&0001
Appli.Inter: USB\VID_12D1&PID_140C&MI_02\6&3A1D2012&0&0002
PC UI Inter: USB\VID_12D1&PID_140C&MI_03\6&3A1D2012&0&0003

Reported-by: Thomas Schäfer <tschaefer@t-online.de>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>