drm/radeon: Improve vramlimit module param documentation
drm/radeon: Inline r100_mm_rreg

This was originally un-inlined by Andi Kleen in 2011 citing size concerns.
Indeed, inlining it grows radeon.ko by 7%.

However, 2% of cpu is spent in this function. Inlining it gives 1% more fps
in Urban Terror.
drm/ttm: Add a priority queue
drm/ttm: Add support for using the priority queue instead of LRU
drm/radeon: Enable the priority queue for VRAM
drm/radeon: Update cs ioctl to support scoring