m4: update power profile overlay

Taken from 4.4.2 OTA
m4: wifi doesn't support batched scan
m4: wifi updates

* inherit wifi.interface property from msm8960-common
* remove obsolete / add missing services
* while at it, also drop obsolete bluetooth services
* turns out specifying user and group for wpa_supplicant is not a good idea after all
* disable scan offloading, everybody else does it (did someone say cargo cult?)