drm/amd/pm: Enable GPU metrics for One VF mode

Enable GPU metrics feature in one VF mode.
These are only possible in one VF mode because the VF is dedicated in that case.

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