Turns out my last fix to this broke one case for Rage 128 Pro so
revert that part of previous patch. This now fixes the remaining
rendering problems for MorphOS which now can produce picture with
-device ati-vga (although it may not be optimised yet and video
overlay emulation is still known to be missing).

Fixes: 866ad5f5
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Message-id: da33261a841755691f698db8190c868df0c0d3ae.1562276605.git.balaton@eik.bme.hu
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>