This patch adds the Unpack Signed Word instructions introduced in
Power ISA Version 2.07:

  - Vector Unpack High Signed Word (vupkusw)
  - Vector Unpack Low Signed Word (vupklsw)
Signed-off-by: NTom Musta <tommusta@gmail.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>