allwinner-ahci: Remove user_creatable flag

allwinner-ahci needs its IRQ to be connected and mmio to be
mapped (this is done by the alwinner-a10 device realize method),
and won't work with -device. Remove the user_creatable flag from
the device class.

Cc: John Snow <jsnow@redhat.com>
Cc: qemu-block@nongnu.org
Cc: Beniamino Galvani <b.galvani@gmail.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: qemu-arm@nongnu.org
Cc: Marcel Apfelbaum <marcel@redhat.com>
Acked-by: NJohn Snow <jsnow@redhat.com>
Acked-by: NMarcel Apfelbaum <marcel@redhat.com>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Message-Id: <20170503203604.31462-12-ehabkost@redhat.com>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>

hw/ide/ahci.c

@@ -1815,11 +1815,6 @@ static void allwinner_ahci_class_init(ObjectClass *klass, void *data)
     DeviceClass *dc = DEVICE_CLASS(klass);
 
     dc->vmsd = &vmstate_allwinner_ahci;
-    /*
-     * FIXME: Set only because we are not sure yet if this device
-     * will be outside the q35 sysbus whitelist.
-     */
-    dc->user_creatable = true;
 }
 
 static const TypeInfo allwinner_ahci_info = {