dt-bindings: Add Hycon Technology vendor prefix

Update Documentation/devicetree/bindings/vendor-prefixes.yaml to
include "hycon" as a vendor prefix for "Hycon Technology".
Company website: https://www.hycontek.com/



Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
Reviewed-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210413144446.2277817-2-giulio.benetti@benettiengineering.com


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>