esp_netif: update netsuite test example to use I/O driver configuration

closes https://github.com/espressif/esp-idf/issues/4403

examples/system/network_tests/main/stdinout.h

@@ -0,0 +1,36 @@
+// Copyright 2019 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef _NET_SUITE_STDINOUT_H
+#define _NET_SUITE_STDINOUT_H
+
+/**
+ * @brief Gets one packet from stdin
+ *
+ * @param packet ptr to the packet buffer
+ * @param max_len maximum size of allocated data buffer
+ *
+ * @return actual size of received packet (-1 in case of error)
+ */
+
+ssize_t netsuite_io_get_packet(char *packet, size_t max_len);
+
+/**
+ * @brief Initializes the I/O object handle to be attached to esp-netif instance
+ *
+ * @return I/O object pointer
+ */
+void * netsuite_io_new(void);
+
+#endif //_NET_SUITE_STDINOUT_H