sched/topology: Optimize topology_span_sane()

JIRA: https://issues.redhat.com/browse/RHEL-39277
Tested: Sanity tested on normal sized systems. This will
need other qa for the 3840 cpu system test.

These simple patches reduce the 0(n^2) code in
build_sched_domains() a bit which avoids a soft lockup
on large (very large) cpu systems.

Signed-off-by: Phil Auld pauld@redhat.com