drm/amdgpu: fix uvd can't initialized when dpm disabled on Ci.

need to start smc when dpm disabled.
otherwise, uvd can't get response from smu.
so uvd ring test and ib test will timeout.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>