[PATCH] powerpc numa: Minor cpu hotplug-related cleanups

map_cpu_to_node does not need to be inline, it is never called in a
hot path.

map_cpu_to_node, numa_setup_cpu, and find_cpu_node can be marked
__cpuinit, as they are never used after boot if CONFIG_HOTPLUG_CPU=n.

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