Add helpers to iterate over all entries in a bo_list.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chunming  Zhou <david1.zhou@amd.com>
Acked-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>