pinctrl: stop using gpiod_to_chip()

Don't dereference struct gpio_chip directly, use dedicated gpio_device
getters instead.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20231115165001.2932350-3-brgl@bgdev.pl


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>