dt-bindings: add vendor-prefix for Newhaven Display

Newhaven Display provides the worldwide marketplace with cost
effective high quality display devices ranging from OLED and LCD
Displays to VFD Displays.

Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
Reviewed-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Rob Herring <robh@kernel.org>