[PATCH] powerpc: numa placement for dynamically added memory

This places dynamically added memory within the appropriate
numa node.  A new routine hot_add_scn_to_nid() replicates most of
the memory scanning code in parse_numa_properties().

Signed-off-by: Mike Kravetz <kravetz@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>