unzip: new package

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Cc: Romain Naour <romain.naour@openwide.fr>
Cc: Jan Pedersen <jp@jp-embedded.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>