drm/amd/powerplay: Partially revert change initialize platform caps

partially revert commit I36f3c9e3a28cbf290652edfb6e19109da660c4f1
this will lead APU can't work.

Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>