Right now we have all firmware packages under firmware/*.
This is problematic for mainly two reasons:
- It's not immediately clear which firmware packages we need to keep
when forking a new stable branch. (Where we delete testing devices
at the moment...) We might end up deleting firmware packages that
are actually used by one of the devices in community.
- When backporting devices to the stable we cannot just cherry-pick
the commit that moved the device to community (since it does not
contain the firmware package). Instead we need to cherry-pick
earlier commits as well, which may touch a lot of deleted files
in the testing directory.
Let's make this consistent by also placing the firmware packages in
the device/* directory. We already have the common firmware- prefix
to distinguish them from device/kernel packages, which are already
both under the device/* directory.
