tty: serial: of_serial: Fix module autoload for OF platform driver

This platform driver has a OF device ID table but the OF module
alias information is not created so module autoloading won't work.

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
index 10d8c93..e08df97 100644
--- a/drivers/tty/serial/of_serial.c
+++ b/drivers/tty/serial/of_serial.c
@@ -354,6 +354,7 @@
 #endif
 	{ /* end of list */ },
 };
+MODULE_DEVICE_TABLE(of, of_platform_serial_table);
 
 static struct platform_driver of_platform_serial_driver = {
 	.driver = {