dt-bindings: Add vendor prefix for Evervision Electronics

Evervision Electronics is a panel manufacturer from Taipei.
http://www.evervisionlcd.com/index.php?lang=en



Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190416100645.21689-2-m.felsch@pengutronix.de