the case could happen when gpu reset:
1. when gpu reset, cs can be continue until sw queue is full, then push job will wait with holding pd reservation.
2. gpu_reset routine will also need pd reservation to restore page table from their shadow.
3. cs is waiting for gpu_reset complete, but gpu reset is waiting for cs releases reservation.

v2: handle amdgpu_cs_submit error path.
Signed-off-by: Chunming Zhou <David1.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Junwei Zhang <Jerry.Zhang@amd.com>
Reviewed-by: Monk Liu <monk.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>