[PATCH] powerpc numa: Minor debugging code changes

Add debug statement for map_cpu_to_node; it's useful for cpu hotplug.

Clarify debug statement about not finding the numa reference points
property.

Don't print a meaningless associativity depth (-1) on non-numa systems.

Signed-off-by: Nathan Lynch <nathanl@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>