libc-vdso.h place consolidation

This patch moves the libc-vdso.h internal header from bits folder to
default architecture one and also corrects the remaning includes in
the files.

sysdeps/unix/sysv/linux/s390/libc-vdso.h

@@ -0,0 +1,34 @@
+/* Resolve function pointers to VDSO functions.
+   Copyright (C) 2008-2015 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+
+#ifndef _LIBC_VDSO_H
+#define _LIBC_VDSO_H
+
+#ifdef SHARED
+
+extern long int (*__vdso_gettimeofday) (struct timeval *, void *)
+  attribute_hidden;
+
+extern long int (*__vdso_clock_gettime) (clockid_t, struct timespec *);
+
+extern long int (*__vdso_clock_getres) (clockid_t, struct timespec *);
+
+#endif
+
+#endif /* _LIBC_VDSO_H */