x86/apic: Build the x86 topology enumeration functions on UP APIC builds too

These functions are mostly pointless on UP, but nevertheless the
64-bit UP APIC build already depends on the existence of
topology_apply_cmdline_limits_early(), which caused a build bug,
resolve it by making them available under CONFIG_X86_LOCAL_APIC,
as their prototypes already are.
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/cpu/topology.c

@@ -344,7 +344,7 @@ void topology_hotunplug_apic(unsigned int cpu)
 }
 #endif
 
-#ifdef CONFIG_SMP
+#ifdef CONFIG_X86_LOCAL_APIC
 static unsigned int max_possible_cpus __initdata = NR_CPUS;
 
 /**