zephyr/modusocket: Enable stream write() method.

zephyr/modusocket.c

@@ -449,6 +449,8 @@ STATIC const mp_map_elem_t socket_locals_dict_table[] = {
     { MP_OBJ_NEW_QSTR(MP_QSTR_accept), (mp_obj_t)&socket_accept_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_send), (mp_obj_t)&socket_send_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_recv), (mp_obj_t)&socket_recv_obj },
+
+    { MP_OBJ_NEW_QSTR(MP_QSTR_write), (mp_obj_t)&mp_stream_write_obj },
 };
 STATIC MP_DEFINE_CONST_DICT(socket_locals_dict, socket_locals_dict_table);