When a user unmaps a userq VA, the driver must ensure
the queue has no in-flight jobs. If there is pending work,
the kernel should wait for the attached eviction (bookkeeping)
fence to signal before deleting the mapping.
Suggested-by: Christian König <christian.koenig@amd.com> Signed-off-by: Prike Liang <Prike.Liang@amd.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>