drm/amd/amdgpu: Cleanup gfxhub read-modify-write patterns

Signed-off-by: Tom St Denis <tom.stdenis@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Tom St Denis 2017-06-12 12:30:41 -04:00 • committed by Alex Deucher
commit 805cb75ccb