gpio: use new gpio_set_config() helper in more places

As suggested by Linus Walleij, let's use the new gpio_set_config()
helper in gpiod_set_debounce() and gpiod_set_transitory().

Signed-off-by: Thomas Petazzoni <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/gpio/gpiolib.c

···
 	}
 
 	config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
-	return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
+	return gpio_set_config(chip, gpio_chip_hwgpio(desc), config);
 }
 EXPORT_SYMBOL_GPL(gpiod_set_debounce);
 
···
 	packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
 					  !transitory);
 	gpio = gpio_chip_hwgpio(desc);
-	rc = chip->set_config(chip, gpio, packed);
+	rc = gpio_set_config(chip, gpio, packed);
 	if (rc == -ENOTSUPP) {
 		dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
 				gpio);