Add SMB2 lsa helper routines

Signed-off-by: David Mulder <dmulder@suse.com>
Reviewed-by: Noel Power <noel.power@suse.com>
Reviewed-by: Jeremy Allison <jra@samba.org>
(cherry picked from commit 3763052c2a95ac9bd60f00458389a5245cf5d58d)
