memory: omap-gpmc: remove GPIO set() and direction_output() callbacks

This driver implements an input-only GPIO controller. There's no need to
implement the set() and direction_output() callbacks in this case, the
GPIO core will handle it.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://lore.kernel.org/r/20250407-gpiochip-set-rv-memory-v1-2-5ab0282a9da7@linaro.org


Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>