of: add vendor prefix for Ka-Ro electronics GmbH

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/vendor-prefixes.txt

@@ -39,6 +39,7 @@ ibm	International Business Machines (IBM)
 idt	Integrated Device Technologies, Inc.
 img	Imagination Technologies Ltd.
 intercontrol	Inter Control Group
+karo	Ka-Ro electronics GmbH
 lg	LG Corporation
 linux	Linux-specific binding
 lsi	LSI Corp. (LSI Logic)