motorola-montana: add support for WiFi
This merge request includes new firmware package for Motorola Moto G5s and nonfree-firmware subpackage in device-motorola-montana
.
Firmware package is split in 3 subpackages: wcnss
, adsp
and modem
. This is done so I can include only WiFi firmware to default installation, but add audio or modem firmware when I need to test them.