[PATCH] fix include/linux/smp.h

This patch adds #include <linux/threads.h> to include/linux/smp.h,
because it (smp.h) needs the definition of NR_CPUS.  (It so happens
that include/asm-i386/smp.h includes <linux/threads.h>, but IMHO
include/linux/smp.h shouldn't rely on that).

include/linux/smp.h

@@ -12,6 +12,7 @@
 
 #include <linux/kernel.h>
 #include <linux/compiler.h>
+#include <linux/threads.h>
 #include <asm/smp.h>
 
 /*