dt-bindings: Add vendor prefix for emtrion GmbH

emtrion is a system integrator and manufacturer of embedded systems.

Website: https://www.emtrion.de

Signed-off-by: Jan Tuerk <jan.tuerk@emtrion.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171123125600.41562-3-jan.tuerk@emtrion.com

Documentation/devicetree/bindings/vendor-prefixes.txt

@@ -104,6 +104,7 @@ eeti	eGalax_eMPIA Technology Inc
 elan	Elan Microelectronic Corp.
 embest	Shenzhen Embest Technology Co., Ltd.
 emmicro	EM Microelectronic
+emtrion	emtrion GmbH
 energymicro	Silicon Laboratories (formerly Energy Micro AS)
 engicam	Engicam S.r.l.
 epcos	EPCOS AG