[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/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
index adc8a26a..7d9444a 100644
--- a/arch/arm/mach-omap2/serial.c
+++ b/arch/arm/mach-omap2/serial.c
@@ -17,8 +17,7 @@
 #include <linux/serial_8250.h>
 #include <linux/serial_reg.h>
 #include <linux/clk.h>
-
-#include <asm/io.h>
+#include <linux/io.h>
 
 #include <mach/common.h>
 #include <mach/board.h>