gpio: twl6040: set line value in .direction_out()

It's ok for a GPIO controller to be output-only but the .direction_out()
callback must also set the requested line value.

Link: https://lore.kernel.org/r/20250707-gpiochip-set-rv-gpio-round4-v1-9-35668aaaf6d2@linaro.org


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