drm/amdgpu: change default sched jobs to 32

Change the default scheduler queue size from 16 to 32.

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>