drm/amdgpu/gfx8: cache rb config values

Needed when for SR-IOV and when PG is enabled.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Alex Deucher 2016-10-10 11:15:24 -04:00
commit 392f0c775c