x86/time: Make setup_default_timer_irq() static

This function isn't used outside of time.c, so let's mark it static.

Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1497321029-29049-1-git-send-email-douly.fnst@cn.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/kernel/time.c b/arch/x86/kernel/time.c
index d39c091..e0754cd 100644
--- a/arch/x86/kernel/time.c
+++ b/arch/x86/kernel/time.c
@@ -66,7 +66,7 @@ static struct irqaction irq0  = {
 	.name = "timer"
 };
 
-void __init setup_default_timer_irq(void)
+static void __init setup_default_timer_irq(void)
 {
 	if (!nr_legacy_irqs())
 		return;