x86: remove dead code and exports

No users.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/process_64.c

@@ -72,13 +72,6 @@ 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(idle_notifier_unregister);
 
 void enter_idle(void)
 {

include/asm-x86/idle.h

@@ -6,7 +6,6 @@
 
 struct notifier_block;
 void idle_notifier_register(struct notifier_block *n);
-void idle_notifier_unregister(struct notifier_block *n);
 
 void enter_idle(void);
 void exit_idle(void);