drm/amd/pp: Cleaning up vega10_enable_dpm_tasks function

1. move display num initialize out of dpm enable tasks.
2. do not set/restore smc telemetry if dpm is runing.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>