dt-bindings: Add vendor prefix for DLC Display Co., Ltd.

DLC provides a wide range of display solutions.
Website: http://www.dlcdisplay.com/Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: NMarco Felsch <m.felsch@pengutronix.de>
Reviewed-by: NRob Herring <robh@kernel.org>
Signed-off-by: NThierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180523092504.5142-2-m.felsch@pengutronix.de

Documentation/devicetree/bindings/vendor-prefixes.txt

@@ -94,6 +94,7 @@ dh	DH electronics GmbH
 digi	Digi International Inc.
 digilent	Diglent, Inc.
 dioo	Dioo Microcircuit Co., Ltd
+dlc	DLC Display Co., Ltd.
 dlg	Dialog Semiconductor
 dlink	D-Link Corporation
 dmo	Data Modul AG