Try to lock moved BOs if it's successful we can update the
PTEs directly to the new location.

v2: rebase
Signed-off-by: NChristian König <christian.koenig@amd.com>
Acked-by: NFelix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>