x86, NUMA: Unify 32/64bit numa_cpu_node() implementation

Currently, the only meaningful user of apic->x86_32_numa_cpu_node() is
NUMAQ which returns valid mapping only after CPU is initialized during
SMP bringup; thus, the previous patch to set apicid -> node in
setup_local_APIC() makes __apicid_to_node[] always contain the correct
mapping whether custom apic->x86_32_numa_cpu_node() is used or not.

So, there is no reason to keep separate 32bit implementation.  We can
always consult __apicid_to_node[].  Move 64bit implementation from
numa_64.c to numa.c and remove 32bit implementation from numa_32.c.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
diff --git a/arch/x86/include/asm/numa.h b/arch/x86/include/asm/numa.h
index a50fc9f..5982d41 100644
--- a/arch/x86/include/asm/numa.h
+++ b/arch/x86/include/asm/numa.h
@@ -1,6 +1,8 @@
 #ifndef _ASM_X86_NUMA_H
 #define _ASM_X86_NUMA_H
 
+#include <linux/nodemask.h>
+
 #include <asm/topology.h>
 #include <asm/apicdef.h>
 
@@ -22,10 +24,18 @@
 {
 	__apicid_to_node[apicid] = node;
 }
+
+extern int __cpuinit numa_cpu_node(int cpu);
+
 #else	/* CONFIG_NUMA */
 static inline void set_apicid_to_node(int apicid, s16 node)
 {
 }
+
+static inline int numa_cpu_node(int cpu)
+{
+	return NUMA_NO_NODE;
+}
 #endif	/* CONFIG_NUMA */
 
 #ifdef CONFIG_X86_32