x86: declare setup_apic_routing

Global functions need a prototype.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/include/asm-x86/genapic_64.h b/include/asm-x86/genapic_64.h
index 1de931b..0f85046 100644
--- a/include/asm-x86/genapic_64.h
+++ b/include/asm-x86/genapic_64.h
@@ -44,4 +44,6 @@
 extern void uv_cpu_init(void);
 extern int uv_wakeup_secondary(int phys_apicid, unsigned int start_rip);
 
+extern void setup_apic_routing(void);
+
 #endif