Allow SD_NODES_PER_DOMAIN to be overridden.  On ppc64 set this at 16 so our
top level scheduling domains will include all nodes.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>