of: unittest: Switch to use fwnode instead of of_node

The OF node in the GPIO library is deprecated and soon will be removed.
GPIO library now accepts fwnode as a firmware node, so switch the module
to use it instead.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220708214539.7254-1-andriy.shevchenko@linux.intel.com

drivers/of/unittest.c

@@ -1602,7 +1602,7 @@ static int unittest_gpio_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, devptr);
 
-	devptr->chip.of_node = pdev->dev.of_node;
+	devptr->chip.fwnode = dev_fwnode(&pdev->dev);
 	devptr->chip.label = "of-unittest-gpio";
 	devptr->chip.base = -1; /* dynamic allocation */
 	devptr->chip.ngpio = 5;
@@ -1611,7 +1611,7 @@ static int unittest_gpio_probe(struct platform_device *pdev)
 	ret = gpiochip_add_data(&devptr->chip, NULL);
 
 	unittest(!ret,
-		 "gpiochip_add_data() for node @%pOF failed, ret = %d\n", devptr->chip.of_node, ret);
+		 "gpiochip_add_data() for node @%pfw failed, ret = %d\n", devptr->chip.fwnode, ret);
 
 	if (!ret)
 		unittest_gpio_probe_pass_count++;