drm/amd/pm: change smu msg's attribute to allow working under sriov

the following message is allowed in sriov mode:
1. GetEnabledSmuFeaturesLow
2. GetEnabledSmuFeaturesHigh

Signed-off-by: Kevin Wang <kevin1.wang@amd.com>
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>