port-mbim: increase timeout of device open operation

A MBIM device typically delays its response to an 'Open' command when it
has not completed the initialization process. This patch increases the
timeout of the MBIM device open operation from 10s to 30s to handle
situations where the device takes much longer to initialize.

src/mm-port-mbim.c

@@ -111,7 +111,7 @@ mbim_device_new_ready (GObject *unused,
 
     /* Now open the MBIM device */
     mbim_device_open (ctx->self->priv->mbim_device,
-                      10,
+                      30,
                       ctx->cancellable,
                       (GAsyncReadyCallback)mbim_device_open_ready,
                       ctx);