dt-bindings: add vendor prefix for NLT Technologies, Ltd.

NLT technologies is the former NEC display business, but changed its
name to NLT Technologies when forming a joint venture with
Shenzhen AVIC OPTOELECTRONICS, Ltd.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170608180758.31020-2-l.stach@pengutronix.de

Documentation/devicetree/bindings/vendor-prefixes.txt

@@ -219,6 +219,7 @@ nexbox	Nexbox
 newhaven	Newhaven Display International
 ni	National Instruments
 nintendo	Nintendo
+nlt	NLT Technologies, Ltd.
 nokia	Nokia
 nordic	Nordic Semiconductor
 nuvoton	Nuvoton Technology Corporation