Adds power management support for vega10.

v2: squash in fan control and led config fixes from Rex
v3: squash in dead code removal and socvid fixes from Rex
v4: squash in dpm force level fix from Rex
v5: squash in latest headless, gpu load fixes from Rex
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Eric Huang <JinHuiEric.Huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>