drm/amdgpu: drop a dummy wakeup scheduler

since the dependency job is also scheduled by the same
scheduler with the job depended on it, no need to
call wake up scheduler when the dep is scheduled.

Signed-off-by: Monk Liu <Monk.Liu@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>