feat(esp_libc): add full support for picolibc

components/newlib/platform_include/sys/unistd.h

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2018-2022 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2018-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -7,6 +7,11 @@
 #pragma once
 
 #include <sys/types.h>
+#include "sdkconfig.h"
+
+#if CONFIG_LIBC_PICOLIBC_NEWLIB_COMPATIBILITY
+#include <sys/select.h>
+#endif
 
 #include_next <sys/unistd.h>