amd/powerplay: enable uclk dpm

Enable uclk dpm on navi10 as the result of
removing fast switch setting.

Signed-off-by: Kenneth Feng <kenneth.feng@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>