qmi_wwan: Added support for Telit LN940 series

Added support for the Telit LN940 series cellular modules QMI interface.
QMI_QUIRK_SET_DTR quirk requied for Qualcomm MDM9x40 chipset.

Signed-off-by: Jörgen Storvist <jorgen.storvist@gmail.com>
Acked-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>