gpio: ml-ioh: use new GPIO line value setter callbacks

struct gpio_chip now has callbacks for setting line values that return
an integer, allowing to indicate failures. Convert the driver to using
them.

Link: https://lore.kernel.org/r/20250506-gpiochip-set-rv-gpio-part3-v1-12-0fbdea5a9667@linaro.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Author: Bartosz Golaszewski

drivers/gpio/gpio-ml-ioh.c

@@ -89,7 +89,7 @@ struct ioh_gpio {
 
 static const int num_ports[] = {6, 12, 16, 16, 15, 16, 16, 12};
 
-static void ioh_gpio_set(struct gpio_chip *gpio, unsigned nr, int val)
+static int ioh_gpio_set(struct gpio_chip *gpio, unsigned int nr, int val)
 {
 	u32 reg_val;
 	struct ioh_gpio *chip =	gpiochip_get_data(gpio);
@@ -104,6 +104,8 @@ static void ioh_gpio_set(struct gpio_chip *gpio, unsigned nr, int val)
 
 	iowrite32(reg_val, &chip->reg->regs[chip->ch].po);
 	spin_unlock_irqrestore(&chip->spinlock, flags);
+
+	return 0;
 }
 
 static int ioh_gpio_get(struct gpio_chip *gpio, unsigned nr)
@@ -222,7 +224,7 @@ static void ioh_gpio_setup(struct ioh_gpio *chip, int num_port)
 	gpio->direction_input = ioh_gpio_direction_input;
 	gpio->get = ioh_gpio_get;
 	gpio->direction_output = ioh_gpio_direction_output;
-	gpio->set = ioh_gpio_set;
+	gpio->set_rv = ioh_gpio_set;
 	gpio->dbg_show = NULL;
 	gpio->base = -1;
 	gpio->ngpio = num_port;