sys: posix: remove not needed strings.h

sys/posix/include/strings.h

@@ -1,51 +0,0 @@
-/*
- * Copyright (C) 2013  INRIA.
- *
- * This file is subject to the terms and conditions of the GNU Lesser
- * General Public License v2.1. See the file LICENSE in the top level
- * directory for more details.
- */
-
-/**
- * @ingroup     posix
- * @{
- *
- * @file
- * @brief   string operations
- *
- * @see     <a href="http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/strings.h.html">
- *              The Open Group Base Specifications Issue 7, <strings.h>
- *          </a>
- *
- * @author  Martine Lenders <mlenders@inf.fu-berlin.de>
- */
-#ifndef STRINGS_H
-#define STRINGS_H
-
-#include <sys/types.h>
-#include <stddef.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-/**
- * @brief   Returns the position of the first (least significant) bit set in
- *          integer *i*, or 0 if no bits are set in i.
- *
- * @param[in] i    an integer number.
- *
- * @return  Position (1 for least significant bit) of the first bit set,
- *          0 if no bits are set.
- *
- * @see <a href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/ffs.html">
- *          The Open Group Base Specification Issue 7, ffs
- *      </a>
- */
-#define ffs(i) __builtin_ffs(i)
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* STRINGS_H */