drm/amd/powerplay: set fan target temperature by msg on vega10.

SMU not support FanTargetTemperature in pptable,
so send msg instand.

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>