drm/amd/powerplay: let PMFW to handle the features disablement on BACO in V2

For Sienna_Cichlid, PMFW will handle the features disablement on BACO in. No
need to have driver stepped in.

V2: limit this for baco really

Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Likun Gao <Likun.Gao@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>