Merge tag 'amd-drm-fixes-5.12-2021-03-18' of https://gitlab.freedesktop.org/agd5f/linux into drm-fixes

amdgpu:
- DCN 3.0 gamma fixes
- DCN 2.1 corrupt screen fix

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210318042858.3810-1-alexander.deucher@amd.com