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/kernel/cevt-r4k.c b/arch/mips/kernel/cevt-r4k.c
index 0015e44..2652362 100644
--- a/arch/mips/kernel/cevt-r4k.c
+++ b/arch/mips/kernel/cevt-r4k.c
@@ -9,6 +9,7 @@
 #include <linux/clockchips.h>
 #include <linux/interrupt.h>
 #include <linux/percpu.h>
+#include <linux/smp.h>
 
 #include <asm/smtc_ipi.h>
 #include <asm/time.h>