of: add vendor prefix for Holtek Semiconductor

This patch introduces a vendor prefix for Holtek Semiconductor Inc.
Signed-off-by: Robin van der Gracht <robin@protonic.nl>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/vendor-prefixes.txt

@@ -126,6 +126,7 @@ hitex	Hitex Development Tools
 holt	Holt Integrated Circuits, Inc.
 honeywell	Honeywell
 hp	Hewlett Packard
+holtek	Holtek Semiconductor, Inc.
 i2se	I2SE GmbH
 ibm	International Business Machines (IBM)
 idt	Integrated Device Technologies, Inc.