x86: replace CONFIG_X86_SMP with CONFIG_SMP

The x86/Voyager subarch used to have this distinction between
 'x86 SMP support' and 'Voyager SMP support':

 config X86_SMP
	bool
	depends on SMP && ((X86_32 && !X86_VOYAGER) || X86_64)

This is a pointless distinction - Voyager can (and already does) use
smp_ops to implement various SMP quirks it has - and it can be extended
more to cover all the specialities of Voyager.

So remove this complication in the Kconfig space.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index e645d47..eeb180b 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -588,7 +588,7 @@
 
 static int __init default_update_genapic(void)
 {
-#ifdef CONFIG_X86_SMP
+#ifdef CONFIG_SMP
 	if (!apic->wakeup_cpu)
 		apic->wakeup_cpu = wakeup_secondary_cpu_via_init;
 #endif