drm/amd/powerplay: move smu_feature_update_enable_state to up level

this function is not ip or asic related function,
so move it to top level as public api in smu.

Signed-off-by: Kevin Wang <kevin1.wang@amd.com>
Reviewed-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Kenneth Feng <kenneth.feng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>