gpio: wcd934x: check the return value of regmap_update_bits()

regmap_update_bits() can fail so check its return value in
wcd_gpio_direction_output() for consistency with the rest of the code
and propagate any errors.

Link: https://lore.kernel.org/r/20250709-gpiochip-set-rv-gpio-remaining-v1-2-b8950f69618d@linaro.org


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