NOHZ: unify the nohz function calls in irq_enter()

We have two separate nohz function calls in irq_enter() for no good
reason. Just call a single NOHZ function from irq_enter() and call
the bits in the tick code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

kernel/softirq.c

@@ -265,16 +265,12 @@ asmlinkage void do_softirq(void)
  */
 void irq_enter(void)
 {
-#ifdef CONFIG_NO_HZ
 	int cpu = smp_processor_id();
+
 	if (idle_cpu(cpu) && !in_interrupt())
-		tick_nohz_stop_idle(cpu);
-#endif
+		tick_check_idle(cpu);
+
 	__irq_enter();
-#ifdef CONFIG_NO_HZ
-	if (idle_cpu(cpu))
-		tick_nohz_update_jiffies();
-#endif
 }
 
 #ifdef __ARCH_IRQ_EXIT_IRQS_DISABLED