memory-hotplug: cleanup: removing the arch specific functions without any implementation

memory-hotplug: cleanup: removing the arch specific functions without any implementation

After introducing CONFIG_HAVE_BOOTMEM_INFO_NODE Kconfig option, the
related arch specific functions become confusing, remove them.

Guys who want to implement memory-hotplug feature on such archs for this
part should look into register_page_bootmem_info_node() and flesh out from
top to end.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Lin Feng <linfeng@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>