Iterate through same-type objects covering at least CPU set
NULL, return the first object of type
type covering at least part of CPU set
set. The next invokation should pass the previous return value in
prev so as to obtain the next object of type
type covering at least another part of
If there are no or multiple depths for type
NULL is returned. The caller may fallback to hwloc_get_next_obj_covering_cpuset_by_depth() for each depth.