drm/amd/pm: Enable sysfs required by rocm-smi tool for One VF mode

Enable power level, power limit and fan speed
information retrieval in one VF mode.
This is required so that tool ROCM-SMI
can provide this information to users.

Signed-off-by: Marina Nikolic <Marina.Nikolic@amd.com>
Acked-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Kevin Wang <kevinyang.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>