drm/amd/powerplay: delete dpm code for Cz/St.

The powerplay implementation has been the default for a
while now.

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