drm/amd/pm: drop redundant and unneeded BACO APIs V2

Use other APIs which are with the same functionality but much
more clean.

V2: drop mediate unneeded interface

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