dt-bindings: vendor-prefixes: add OpenWrt

OpenWrt project (with the help of MediaTek and Banana Pi) has produced
its very first own hardware. It needs its own prefix.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20240527115933.7396-2-zajec5@gmail.com


Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>