x86: unify __cpu_up.

function definition is moved to common header. x86_64 version
is now called native_cpu_up

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/smpboot_64.c b/arch/x86/kernel/smpboot_64.c
index 0880f2c..e381fe7 100644
--- a/arch/x86/kernel/smpboot_64.c
+++ b/arch/x86/kernel/smpboot_64.c
@@ -929,7 +929,7 @@
 /*
  * Entry point to boot a CPU.
  */
-int __cpuinit __cpu_up(unsigned int cpu)
+int __cpuinit native_cpu_up(unsigned int cpu)
 {
 	int apicid = cpu_present_to_apicid(cpu);
 	unsigned long flags;