x86-32, NUMA: use sparse_memory_present_with_active_regions()

Instead of calling memory_present() for each region from NUMA init,
call sparse_memory_present_with_active_regions() from paging_init()
similarly to x86-64.

For flat and numaq, this results in exactly the same memory_present()
calls.  For srat, if there are multiple memory chunks for a node,
after this change, memory_present() will be called separately for each
chunk instead of being called once to encompass the whole range, which
doesn't cause any harm and actually is the better behavior.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>

arch/x86/mm/init_32.c

@@ -716,6 +716,7 @@ void __init paging_init(void)
 	 * NOTE: at this point the bootmem allocator is fully available.
 	 */
 	olpc_dt_build_devicetree();
+	sparse_memory_present_with_active_regions(MAX_NUMNODES);
 	sparse_init();
 	zone_sizes_init();
 }