[IA64] Minimize per_cpu reservations.

This attached patch significantly shrinks boot memory allocation on ia64.
It does this by not allocating per_cpu areas for cpus that can never
exist.

In the case where acpi does not have any numa node description of the
cpus, I defaulted to assigning the first 32 round-robin on the known
nodes..  For the !CONFIG_ACPI  I used for_each_possible_cpu().

Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/kernel/setup.c

@@ -493,6 +493,8 @@ setup_arch (char **cmdline_p)
 	acpi_table_init();
 # ifdef CONFIG_ACPI_NUMA
 	acpi_numa_init();
+	per_cpu_scan_finalize((cpus_weight(early_cpu_possible_map) == 0 ?
+		32 : cpus_weight(early_cpu_possible_map)), additional_cpus);
 # endif
 #else
 # ifdef CONFIG_SMP