[IA64] SMP systems may not have SRAT, still need to mark node0 online.

This only causes a problem in the -mm tree now, but Zou Nan hai and
Shaohua Li sent me this fix so that SMP systems compiled with the
generic kernel (which turns on NUMA and CPUSETS in -mm) won't hit
a BUG_ON in kernel/cpuset.c guarantee_online_mems() which is called
from acpi_early_init()
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/kernel/acpi.c

@@ -437,8 +437,9 @@ acpi_numa_arch_fixup (void)
 {
 	int i, j, node_from, node_to;
 
-	/* If there's no SRAT, fix the phys_id */
+	/* If there's no SRAT, fix the phys_id and mark node 0 online */
 	if (srat_num_cpus == 0) {
+		node_set_online(0);
 		node_cpuid[0].phys_id = hard_smp_processor_id();
 		return;
 	}