qom: Unify type registration

Replace device_init() with generalized type_init().

While at it, unify naming convention: type_init([$prefix_]register_types)
Also, type_init() is a function, so add preceding blank line where
necessary and don't put a semicolon after the closing brace.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Cc: Anthony Liguori <anthony@codemonkey.ws>
Cc: malc <av1474@comtv.ru>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/hw/ac97.c b/hw/ac97.c
index 7bf9171..c0fd019 100644
--- a/hw/ac97.c
+++ b/hw/ac97.c
@@ -1372,9 +1372,9 @@
     .class_init    = ac97_class_init,
 };
 
-static void ac97_register (void)
+static void ac97_register_types (void)
 {
     type_register_static (&ac97_info);
 }
-device_init (ac97_register);
 
+type_init (ac97_register_types)