MIPS: Build fix - include <linux/smp.h> into all smp_processor_id() users.

Some of the were relying into smp.h being dragged in by another header
which of course is fragile.  <asm/cpu-info.h> uses smp_processor_id()
only in macros and including smp.h there leads to an include loop, so
don't change cpu-info.h.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/mm/page.c b/arch/mips/mm/page.c
index 48060c6..f5c7375 100644
--- a/arch/mips/mm/page.c
+++ b/arch/mips/mm/page.c
@@ -10,6 +10,7 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
+#include <linux/smp.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/proc_fs.h>