Also add the other gm20x nouveau firmwares to the source tree to make it easier to add them for someone who can test them. Installed if MKNOUVEAUFIRMWARE is set to 'yes'. This defaults to no except on amd64 and i386 (like for radeon).
of this firmware is controlled by the MKTEGRAFIRMWARE option, which defaults to yes on evbarm and evbarm64 and no everywhere else.