Huawei doesn't support CIND indications, instead it uses some
ofonod: < \r\n^RSSI:23\r\n
Add support for this to atmodem.
please use ofono_netreg_strength_notify for this.
The Huawei specific details with this stupid extra channel need to be
handled inside the Huawei plugin. Cluttering the core with it is not a