ovs: wait for the link to be ready before activating

When activating an ovs-interface we already wait for the cloned MAC
address to be set, ifindex is present and platform link also present but
in some cases this is not enough.

If an udev rule is in place it might modify the interface when it is in
a later stage of the activation causing some race conditions or
problems. In order to solve that, we must wait until the link is fully
initialized.

src/core/devices/ovs/nm-device-ovs-interface.c

@@ -155,6 +155,8 @@ check_waiting_for_link(NMDevice *device, const char *from)
         reason = "no ifindex";
     } else if (!(pllink = nm_platform_link_get(platform, ip_ifindex))) {
         reason = "platform link not found";
+    } else if (!pllink->initialized) {
+        reason = "link is not ready yet";
     } else if (priv->wait_link.cloned_mac
                && !nm_utils_hwaddr_matches(priv->wait_link.cloned_mac,
                                            -1,