* Add nonfree_firmware subpackage to all devices, that depend on
nonfree firmware.
* Some packages were depending on `linux-firmware`, but without having
Wifi working. Removed that dependency as it was probably added by
accident. If it was really necessary, chosing the appropriate
split linux-firmware package (e.g. linux-firmware-brcm) is better
anyway (that has been changed recently in Alpine and is possible
now).
* Add a test case that makes sure we don't have firmware depends
without subpackages in device aports anymore.
