This patch adds the Vector Pack Doubleword instructions introduced in
Power ISA Version 2.07:

 - Vector Pack Signed Doubleword Signed Saturate (vpksdss)
 - Vector Pack Signed Doubleword Unsigned Saturate (vpksdus)
 - Vector Pack Unsigned Doubleword Unsigned Modulo (vpkudum)
 - Vector Pack Unsigned Doubleword Unsigned Saturate (vpkudus)
Signed-off-by: NTom Musta <tommusta@gmail.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>