drm/amd/powerplay: add support to set performance level for sienna_cichlid

drm/amd/powerplay: add support to set performance level for sienna_cichlid

Support for performance level set for sienna_cichlid.
Set standard performance level not fully support, will set to auto
performance level.
Set peak performance level not fully support, will do nothing with it.
Force clk level only support for 2 level for fine grained DPM.

Signed-off-by: Likun Gao <Likun.Gao@amd.com>
Reviewed-by: Kenneth Feng <kenneth.feng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>