drm/amd/pp: Simplify the create of powerplay instance

use adev as input parameter to create powerplay instance
directly. delete cgs wrap layer for power play create.

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