dt-bindings: vendor-prefixes: Add an entry for Cloos

Carl Cloos Schweisstechnik GmbH develops, manufactures and delivers
welding industrial solutions:

https://www.cloos.de/de-en/



Add a vendor prefix entry for it.

Signed-off-by: Fabio Estevam <festevam@denx.de>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>