[newlib]: Added missing includes

Closes https://github.com/espressif/esp-idf/issues/7498

components/newlib/platform_include/sys/uio.h

@@ -1,21 +1,24 @@
-// Copyright 2018 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 _ESP_PLATFORM_SYS_UIO_H_
-#define _ESP_PLATFORM_SYS_UIO_H_
+/*
+ * SPDX-FileCopyrightText: 2018-2021 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <sys/types.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct iovec;
 
 int writev(int s, const struct iovec *iov, int iovcnt);
 
 ssize_t readv(int fd, const struct iovec *iov, int iovcnt);
 
-#endif // _ESP_PLATFORM_SYS_UIO_H_
+#ifdef __cplusplus
+}
+#endif