mn10300 idle: delete pm_idle

pm_idle on mn10300 served no purpose.
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: linux-am33-list@redhat.com

arch/mn10300/kernel/process.c

@@ -36,12 +36,6 @@
 #include <asm/gdb-stub.h>
 #include "internal.h"
 
-/*
- * power management idle function, if any..
- */
-void (*pm_idle)(void);
-EXPORT_SYMBOL(pm_idle);
-
 /*
  * return saved PC of a blocked thread.
  */
@@ -113,7 +107,6 @@ void cpu_idle(void)
 			void (*idle)(void);
 
 			smp_rmb();
-			idle = pm_idle;
 			if (!idle) {
 #if defined(CONFIG_SMP) && !defined(CONFIG_HOTPLUG_CPU)
 				idle = poll_idle;