drm/amd: add parent for sched fence

Parent of sched fence is hw fence which is to signal sched fence.

Signed-off-by: Chunming Zhou <David1.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
3 files changed