drm/amdgpu: add vega12 to dc support check

DC is used for modesetting on vega12.

Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Feifei Xu <Feifei.Xu@amd.com>
This commit is contained in:
Alex Deucher 2017-09-02 02:05:29 -04:00
commit dca7b4015c