examples: common connect component to use both interfaces at once

examples/common_components/protocol_examples_common/include/protocol_examples_common.h

@@ -57,8 +57,22 @@ esp_err_t example_configure_stdin_stdout(void);
 /**
  * @brief Returns esp-netif pointer created by example_connect()
  *
+ * @note If multiple interfaces active at once, this API return NULL
+ * In that case the get_example_netif_from_desc() should be used
+ * to get esp-netif pointer based on interface description
  */
 esp_netif_t *get_example_netif(void);
+
+/**
+ * @brief Returns esp-netif pointer created by example_connect() described by
+ * the supplied desc field
+ *
+ * @param desc Textual interface of created network interface, for example "sta"
+ * indicate default WiFi station, "eth" default Ethernet interface.
+ *
+ */
+esp_netif_t *get_example_netif_from_desc(const char *desc);
+
 #ifdef __cplusplus
 }
 #endif