COMPMID-415: Move DepthConcatenateLayer to new validation

Change-Id: I3e594d5800f563ba9af3195b7db2b6d3e32012dd
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/81340
Reviewed-by: Anthony Barbier <anthony.barbier@arm.com>
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
16 files changed