[adapters]: implement WmtWifiPowerControl for /dev/wmtWifi devices
The code logic is adapted from https://github.com/mer-hybris/sailfish-connman-plugin-suspend and needed to allow entering suspend on MediaTek devices having /dev/wmtWifi character node (mostly tested with Volla Phone, but should be also true for other recent devices we have) with Wi-Fi connection enabled.
This cleans up for review older xenial_-android9-_wmtwifi branch from GitHub repo.
Edited by NotKit