[SUNSU]: Fix license.

FATAL: modpost: GPL-incompatible module sunsu uses the GPL-only symbol tty_insert_flip_string_flags
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/serial/sunsu.c

@@ -1730,3 +1730,4 @@ static void __exit sunsu_exit(void)
 
 module_init(sunsu_probe);
 module_exit(sunsu_exit);
+MODULE_LICENSE("GPL");