core: always pass open port to interface initializations

When the first AT port is grabbed, modem initialization is launched, using that
specific port. This port is also passed to all interface initialization methods.

src/mm-base-modem.c

@@ -266,6 +266,7 @@ mm_base_modem_grab_port (MMBaseModem *self,
                 /* As soon as we get the primary AT port, we initialize the
                  * modem */
                 MM_BASE_MODEM_GET_CLASS (self)->initialize (self,
+                                                            MM_AT_SERIAL_PORT (port),
                                                             NULL, /* TODO: cancellable */
                                                             (GAsyncReadyCallback)initialize_ready,
                                                             NULL);
@@ -707,4 +708,3 @@ mm_base_modem_class_init (MMBaseModemClass *klass)
                              G_PARAM_READWRITE);
     g_object_class_install_property (object_class, PROP_CONNECTION, properties[PROP_CONNECTION]);
 }
-