hw/isa/pc87312: Consolidate the use of device_class_set_parent_realize()

Use device_class_set_parent_realize() to set parent realize() directly.

Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

hw/isa/pc87312.c

@@ -338,10 +338,10 @@ static void pc87312_class_init(ObjectClass *klass, void *data)
     DeviceClass *dc = DEVICE_CLASS(klass);
     ISASuperIOClass *sc = ISA_SUPERIO_CLASS(klass);
 
-    sc->parent_realize = dc->realize;
-    dc->realize = pc87312_realize;
     dc->reset = pc87312_reset;
     dc->vmsd = &vmstate_pc87312;
+    device_class_set_parent_realize(dc, pc87312_realize,
+                                    &sc->parent_realize);
     device_class_set_props(dc, pc87312_properties);
 
     sc->parallel = (ISASuperIOFuncs){