sh: Add export.h to arch/sh specific files as required.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/arch/sh/kernel/perf_event.c b/arch/sh/kernel/perf_event.c
index 2ee21a4..10b14e3 100644
--- a/arch/sh/kernel/perf_event.c
+++ b/arch/sh/kernel/perf_event.c
@@ -25,6 +25,7 @@
 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/perf_event.h>
+#include <linux/export.h>
 #include <asm/processor.h>
 
 struct cpu_hw_events {