drm/radeon: Update to Linux 3.9

Hi,

I've updated the drm/radeon code to match Linux 3.9. The code is here 
[1]. Would be nice if other people could test it
on their radeon devices before I commit.

On my Radeon 3300 it works (initially I got some errors because I did 
not do a full buildkernel!).

Regards,

   Michael

[1]: https://github.com/mneumann/DragonFlyBSD/tree/drm_radeon_linux_3_9