serial: bfin_5xx: pull in linux/io.h for ioremap prototypes

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/serial/bfin_5xx.c b/drivers/serial/bfin_5xx.c
index 6b87955..fcf273e 100644
--- a/drivers/serial/bfin_5xx.c
+++ b/drivers/serial/bfin_5xx.c
@@ -14,6 +14,7 @@
 
 #include <linux/module.h>
 #include <linux/ioport.h>
+#include <linux/io.h>
 #include <linux/init.h>
 #include <linux/console.h>
 #include <linux/sysrq.h>