ppc64: remove some old irq balance related code

arch/ppc64/kernel/idle.c

@@ -84,8 +84,6 @@ int cpu_idle(void)
 	lpaca = get_paca();
 
 	while (1) {
-		irq_stat[smp_processor_id()].idle_timestamp = jiffies;
-
 		if (lpaca->xLpPaca.xSharedProc) {
 			if (ItLpQueue_isLpIntPending(lpaca->lpQueuePtr))
 				process_iSeries_events();
@@ -125,7 +123,6 @@ int cpu_idle(void)
 	long oldval;
 
 	while (1) {
-		irq_stat[smp_processor_id()].idle_timestamp = jiffies;
 		oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
 
 		if (!oldval) {

include/asm-ppc64/hardirq.h

@@ -15,9 +15,7 @@
 
 typedef struct {
 	unsigned int __softirq_pending;
-	unsigned int __syscall_count;
 	struct task_struct * __ksoftirqd_task;
-	unsigned long idle_timestamp;
 } ____cacheline_aligned irq_cpustat_t;
 
 #include <linux/irq_cpustat.h>	/* Standard mappings for irq_cpustat_t above */