[ARM] Convert asm/io.h to linux/io.h

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/plat-omap/mailbox.c b/arch/arm/plat-omap/mailbox.c
index 1d7aec1..b52ce05 100644
--- a/arch/arm/plat-omap/mailbox.c
+++ b/arch/arm/plat-omap/mailbox.c
@@ -30,7 +30,7 @@
 #include <linux/blkdev.h>
 #include <linux/err.h>
 #include <linux/delay.h>
-#include <asm/io.h>
+#include <linux/io.h>
 #include <mach/mailbox.h>
 #include "mailbox.h"