gpio: wm831x: Add basic device tree support

Now the wm831x-core has basic DT support we can update this driver to
allow use of the GPIOs within a device tree system.

Signed-off-by: Charles Keepax <[e-mail]>
Acked-by: Linus Walleij <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>

drivers/gpio/gpio-wm831x.c

···
 static int wm831x_gpio_probe(struct platform_device *pdev)
 {
 	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
-	struct wm831x_pdata *pdata = dev_get_platdata(wm831x->dev);
+	struct wm831x_pdata *pdata = &wm831x->pdata;
 	struct wm831x_gpio *wm831x_gpio;
 	int ret;
 
···
 		wm831x_gpio->gpio_chip.base = pdata->gpio_base;
 	else
 		wm831x_gpio->gpio_chip.base = -1;
+#ifdef CONFIG_OF_GPIO
+	wm831x_gpio->gpio_chip.of_node = wm831x->dev->of_node;
+#endif
 
 	ret = devm_gpiochip_add_data(&pdev->dev, &wm831x_gpio->gpio_chip,
 				     wm831x_gpio);