drm/amdgpu/powerplay: add some definition for other ip block to update cg pg.

Interface for clock and power gating handling.

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