dt-bindings: Add vendor prefix for Elida

Shenzen Elida Technology Co. Ltd. is a Chinese TFT manufacturer.

Signed-off-by: Heiko Stuebner <heiko.stuebner@theobroma-systems.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Rob Herring <robh@kernel.org>