* sysdeps/unix/sysv/linux/bits/mman-linux.h: New file, with
Linux common definitions.
* sysdeps/unix/sysv/linux/sh/bits/mman.h: Remove all defines
provided by bits/mman-linux.h and include <bits/mman-linux.h>.
* sysdeps/unix/sysv/linux/x86/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/s390/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/sh/bits/mman.h: Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/mman.h: Likewise.
