gpiolib: Move of_node operations to gpiolib-of and correct fwnode use

The initial value of the OF node based on presence of parent, but
at the same time this operation somehow appeared separately from others
that handle the OF case. On the other hand there is no need to assign
dev->fwnode in the OF case if code properly retrieves fwnode, i.e.
via dev_fwnode() helper.

Amend gpiolib.c and gpiolib-of.c code in order to group OF operations.

Signed-off-by: Andy Shevchenko <[e-mail]>
Reviewed-by: Linus Walleij <[e-mail]>
Signed-off-by: Bartosz Golaszewski <[e-mail]>

drivers/gpio/gpiolib-of.c

···
 
 void of_gpio_dev_init(struct gpio_chip *gc, struct gpio_device *gdev)
 {
+	/* Set default OF node to parent's one if present */
+	if (gc->parent)
+		gdev->dev.of_node = gc->parent->of_node;
+
 	/* If the gpiochip has an assigned OF node this takes precedence */
 	if (gc->of_node)
 		gdev->dev.of_node = gc->of_node;
 	else
 		gc->of_node = gdev->dev.of_node;
-	if (gdev->dev.of_node)
-		gdev->dev.fwnode = of_fwnode_handle(gdev->dev.of_node);
 }

drivers/gpio/gpiolib.c

···
 	if (!gdev)
 		return -ENOMEM;
 	gdev->dev.bus = &gpio_bus_type;
+	gdev->dev.parent = gc->parent;
 	gdev->chip = gc;
 	gc->gpiodev = gdev;
-	if (gc->parent) {
-		gdev->dev.parent = gc->parent;
-		gdev->dev.of_node = gc->parent->of_node;
-	}
 
 	of_gpio_dev_init(gc, gdev);
 
···
 
 static int gpio_bus_match(struct device *dev, struct device_driver *drv)
 {
+	struct fwnode_handle *fwnode = dev_fwnode(dev);
+
 	/*
 	 * Only match if the fwnode doesn't already have a proper struct device
 	 * created for it.
 	 */
-	if (dev->fwnode && dev->fwnode->dev != dev)
+	if (fwnode && fwnode->dev != dev)
 		return 0;
 	return 1;
 }