R128 Dualhead: WORKING!

[Alex Deucher]

I finally got dualhead working on r128.  It still needs some cleanup
and there are a few bugs I haven't worked out yet:

- modes on crtc2: the right side flickers and has some artifacts
- doesn't play well with the bios: if you have both the crt and the
lcd active when you start X in dualhead mode, both heads will flicker
horribly.  Not sure why yet.  workaround is to switch to lcd only
before starting dualhead X.

Other than that it works fine in basic testing.

Patch available here:
http://freedesktop.org/bugzilla/show_bug.cgi?id=1760
or here:
http://www.botchco.com/alex/r128/r128dh.diff

Feedback and bug fixes welcome.  Once this is fixed up I'll work on
adding mergedfb support.
Please post results/patches here:
http://freedesktop.org/bugzilla/show_bug.cgi?id=1760

x86 xorg cvs binaries:
http://www.botchco.com/alex/r128/ati_drv.o
http://www.botchco.com/alex/r128/r128_drv.o
(you need both)

Alex