syscall: RawSockaddr fix for ppc64, ppc64le

syscall:  RawSockaddr fix for ppc64, ppc64le

    The struct RawSockaddr contains a field Data which
    should be uint8 on ppc64 and ppc64le, but is declared
    as int8 in gccgo.  This change adds a two new files
    which contain the structure declaration for
    RawSockaddr, one with the correct types for for ppc64
    and ppc64le, and the other for non-ppc64 platforms.

    Fixes golang/go#11469

    Reviewed-on: https://go-review.googlesource.com/11946

From-SVN: r226533