drm/amdgpu: Modify unmap_queue format for gfx9 (v6)

1. Modify the unmap_queue package on gfx9. Add trailing fence to track the
   preemption done.
2. Modify emit_ce_meta emit_de_meta functions for the resumed ibs.

v2: Restyle code not to use ternary operator.
v3: Modify code format.
v4: Enable Mid-Command Buffer Preemption for gfx9 by default.
v5: Optimize the flag bit set for emit_fence.
v6: Modify log message for preemption timeout.

Cc: Christian Koenig <Christian.Koenig@amd.com>
Cc: Michel Dänzer <michel@daenzer.net>
Cc: Luben Tuikov <Luben.Tuikov@amd.com>
Signed-off-by: Jiadong.Zhu <Jiadong.Zhu@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>