x86 allow modules to register idle notifiers

needed if the i7300_idle driver is to be modular.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NLen Brown <len.brown@intel.com>

arch/x86/kernel/process_64.c

@@ -62,6 +62,13 @@ void idle_notifier_register(struct notifier_block *n)
 {
 	atomic_notifier_chain_register(&idle_notifier, n);
 }
+EXPORT_SYMBOL_GPL(idle_notifier_register);
+
+void idle_notifier_unregister(struct notifier_block *n)
+{
+	atomic_notifier_chain_unregister(&idle_notifier, n);
+}
+EXPORT_SYMBOL_GPL(idle_notifier_unregister);
 
 void enter_idle(void)
 {