[PATCH] Memory Add Fixes for ppc64

This is a temporary kludge that supports adding all new memory to
node 0.  I will provide a more complete solution similar to that
used for dynamically added CPUs in a few days.

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