qmi_wwan: Add support for Fibocom NL678 series

Added support for Fibocom NL678 series cellular module QMI interface.
Using QMI_QUIRK_SET_DTR required for Qualcomm MDM9x40 series chipsets.

Signed-off-by: Jörgen Storvist <jorgen.storvist@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>