Raven series doesn't support sw smu so far, so we have to add checking to
confirm it return false while the asic is raven.
Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Likun Gao <Likun.Gao@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>