[IA64] Fix UP build with BSP removal support.

Causes undefined force_cpei_retarget defined in arch/ia64/kernel/smpboot.c
Push the unneeded code inside #ifdef CONFIG_HOTPLUG_CPU.
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/kernel/acpi.c

@@ -284,6 +284,7 @@ acpi_parse_plat_int_src(acpi_table_entry_header * header,
 	return 0;
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
 unsigned int can_cpei_retarget(void)
 {
 	extern int cpe_vector;
@@ -319,6 +320,7 @@ void set_cpei_target_cpu(unsigned int cpu)
 {
 	acpi_cpei_phys_cpuid = cpu_physical_id(cpu);
 }
+#endif
 
 unsigned int get_cpei_target_cpu(void)
 {

arch/ia64/kernel/topology.c

@@ -36,7 +36,7 @@ int arch_register_cpu(int num)
 	parent = &sysfs_nodes[cpu_to_node(num)];
 #endif /* CONFIG_NUMA */
 
-#ifdef CONFIG_ACPI
+#if defined (CONFIG_ACPI) && defined (CONFIG_HOTPLUG_CPU)
 	/*
 	 * If CPEI cannot be re-targetted, and this is
 	 * CPEI target, then dont create the control file