bring ia64 nodes online properly

Andi's libnuma exposed the fact that we don't bring nodes online properly as we discover them in ia64. Here's a quick patch to fix that. Tested with Andi's numademo program; seems to work fine.

Jesse

===== arch/ia64/kernel/acpi.c 1.65 vs edited =====

@@ -455,6 +455,7 @@
 	for (i = 0; i < MAX_PXM_DOMAINS; i++) {
 		if (pxm_bit_test(i)) {
 			pxm_to_nid_map[i] = numnodes;
+			node_set_online(numnodes);
 			nid_to_pxm_map[numnodes++] = i;
 		}
 	}