serport: place serport serio device correctly in the device tree

Make serport serio device to be a child of corresponding tty device
instead of just hanging at /sys/devices/serioX.
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/input/serio/serport.c

@@ -165,6 +165,7 @@ static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, u
 	serio->open = serport_serio_open;
 	serio->close = serport_serio_close;
 	serio->port_data = serport;
+	serio->dev.parent = tty->dev;
 
 	serio_register_port(serport->serio);
 	printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty, name));