ia64 used early_node_map[] just to prime free_area_init_nodes(). Now
memblock can be used for the same purpose and early_node_map[] is
scheduled to be dropped. Use memblock instead.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: linux-ia64@vger.kernel.org