drivers/tty/hvc: don't use module_init in non-modular hyp. console code

The HVC_OPAL/RTAS/UDBG/XEN options are all bool, and hence their support
is either present or absent.  It will never be modular, so using
module_init as an alias for __initcall is rather misleading.

Fix this up now, so that we can relocate module_init from
init.h into module.h in the future.  If we don't do this, we'd
have to add module.h to obviously non-modular code, and that
would be a worse thing.

Note that direct use of __initcall is discouraged, vs. one
of the priority categorized subgroups.  As __initcall gets
mapped onto device_initcall, our use of device_initcall
directly in this change means that the runtime impact is
zero -- it will remain at level 6 in initcall ordering.

Also the __exitcall functions have been outright deleted since
they are only ever of interest to UML, and UML will never be
using any of this code.

Cc: Richard Weinberger <richard@nod.at>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/hvc/hvc_rtas.c b/drivers/tty/hvc/hvc_rtas.c
index 0069bb8..08c8792 100644
--- a/drivers/tty/hvc/hvc_rtas.c
+++ b/drivers/tty/hvc/hvc_rtas.c
@@ -102,17 +102,7 @@
 
 	return 0;
 }
-module_init(hvc_rtas_init);
-
-/* This will tear down the tty portion of the driver */
-static void __exit hvc_rtas_exit(void)
-{
-	/* Really the fun isn't over until the worker thread breaks down and
-	 * the tty cleans up */
-	if (hvc_rtas_dev)
-		hvc_remove(hvc_rtas_dev);
-}
-module_exit(hvc_rtas_exit);
+device_initcall(hvc_rtas_init);
 
 /* This will happen prior to module init.  There is no tty at this time? */
 static int __init hvc_rtas_console_init(void)