x86: Use the same node_distance for 32 and 64-bit

The node_distance function is not x86 64-bit specific.  Having
the #ifdef around the extern function declaration and the
 #define causes the default node_distance macro to be used in
asm-generic/topology.h. This also causes a sparse warning in
arch/x86/mm/numa.c when CONFIG_X86_64 is not set:

warning: symbol '__node_distance' was not declared. Should it be
static?

Remove the #ifdef to fix both issues.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NTejun Heo <tj@kernel.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.00.1112061220310.28251@chino.kir.corp.google.comSigned-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/include/asm/topology.h

@@ -130,10 +130,8 @@ extern void setup_node_to_cpumask_map(void);
 	.balance_interval	= 1,					\
 }
 
-#ifdef CONFIG_X86_64
 extern int __node_distance(int, int);
 #define node_distance(a, b) __node_distance(a, b)
-#endif
 
 #else /* !CONFIG_NUMA */