openrisc idle: delete pm_idle

pm_idle() on openrisc was dead code.
Signed-off-by: Len Brown <len.brown@intel.com>
Cc: linux@lists.openrisc.net

arch/openrisc/kernel/idle.c

@@ -39,11 +39,6 @@
 
 void (*powersave) (void) = NULL;
 
-static inline void pm_idle(void)
-{
-	barrier();
-}
-
 void cpu_idle(void)
 {
 	set_thread_flag(TIF_POLLING_NRFLAG);