Update IDF to 9274814 (#767)

* Update IDF to 9274814

* Fix error in i2c and Arduino

tools/sdk/include/lwip/arch/vfs_lwip.h

@@ -0,0 +1,28 @@
+// Copyright 2017 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.
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Internal declarations used to ingreate LWIP port layer
+   to ESP-IDF VFS for POSIX I/O.
+*/
+extern int lwip_socket_offset;
+
+void esp_vfs_lwip_sockets_register();
+
+#ifdef __cplusplus
+}
+#endif