Revert "radeon: just don't map VRAM buffers at all"

This reverts commit 96e8b916a7a39a9ba58e92d1ad77b5501de63ac7.
In the case of VCE encoding with raw YUV file, CPU load directly
to VRAM is faster than combination of CPU writing to GTT and
then blit to VRAM with GPU.

Reviewed-by: Christian König <christian.koenig@amd.com>
1 file changed