qmimodem: use a default RAT when registering

When registering to an operator ofono uses the old RAT.
In the case the modem is not connected to any network, this would use
QMI_NAS_NETWORK_RAT_NONE which results in the error OP_DEVICE_UNSUPPORTED.

Use QMI_NAS_NETWORK_RAT_NO_CHANGE instead to not define any preference.
2 files changed