dt-bindings: Add Marantec vendor prefix

Add vendor prefix for Marantec electronics GmbH.

Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20231016150415.3196-1-cniedermaier@dh-electronics.com


Signed-off-by: Rob Herring <robh@kernel.org>