Comment 11 for bug 1770093

I'm not sure we should be encouraging people to try the installer on the Pi (for which we provide pre-installed images instead); still I don't see any particular harm in adding support for this to ubiquity for those that want to play with it.

The only thing that slightly concerns me with the patch is whether any *other* platforms use /boot/firmware for a non-FAT boot partition, and hence whether the test should be refined to be more Pi-specific? Testing for a "Raspberry Pi" prefix in /proc/device-tree/model would do the trick if that's desired?