Input: initialize serio and gameport at subsystem level

Serio and gameport cores do not depend on other drivers and are
used by code living outside of drivers/input/{gameport|serio}.
Registering them at subsystem level guarantees that they are
fully initialized before anyone tries to use them.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c
index 79e5e77..9666007 100644
--- a/drivers/input/serio/serio.c
+++ b/drivers/input/serio/serio.c
@@ -924,5 +924,5 @@
 	kthread_stop(serio_task);
 }
 
-module_init(serio_init);
+subsys_initcall(serio_init);
 module_exit(serio_exit);