dt-bindings: Add vendor prefix for Ouya Inc.

Ouya is a defunct company from 2012 to 2015.
They produced a single device, the Ouya game console.
In 2015 they were purchased by Razer Inc. and the Ouya was discontinued.
All Ouya services were shuttered in 2019.

Signed-off-by: Peter Geis <pgwipeout@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>