x86/nmi: export local_touch_nmi() symbol for modules

Signed-off-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: NZhang Rui <rui.zhang@intel.com>

arch/x86/kernel/nmi.c

@@ -509,3 +509,4 @@ void local_touch_nmi(void)
 {
 	__this_cpu_write(last_nmi_rip, 0);
 }
+EXPORT_SYMBOL_GPL(local_touch_nmi);