dt-bindings: gpio: fcs,fxl6408: add missing type to GPIO hogs

GPIO hog nodes should define type, otherwise "dummy-hog" boolean
properties would be allowed.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20240828-dt-bindings-gpio-hog-v1-1-63b83e47d804@linaro.org


Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>