ax6 roms don't actually need CGB

[Docheinstein]

trafficstars

At the moment ax6 RTC rooms (ax6/rtc3test-1.gb, ax6/rtc3test-2.gb, ax6/rtc3test-3.gb) require CGB to run, but they can actually work also on DMG.

I think we can remove model=CGB for these and use DMG screenshots instead, so that they can run also on emulators not supporting GCB. What do you think?

[daid]

Sounds like an unintentional thing indeed.