drm/amdgpu: move vcn ring test to amdgpu_vcn.c

Hope it will be generic for vcn later

Signed-off-by: Leo Liu <leo.liu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
3 files changed