dt-bindings: Add vendor prefix for Orise Technology

Orise Technology is headquartered in Taiwan and specializes
in manufacture of Flat Panel Display Driver IC and Flat Panel
Display Controller IC.

Signed-off-by: Philippe CORNU <philippe.cornu@st.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1500297593-30633-2-git-send-email-philippe.cornu@st.com