gpio: pch: fix non-DT build

commit 1cfadea8f395e3fb6a15ea548e3e86c8b6d64f98
"gpio: pch: allow use from device tree"
makes the driver not compile unless CONFIG_OF_GPIO is set.
Fix it.

Cc: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpio-pch.c b/drivers/gpio/gpio-pch.c
index a650a6c..af0715f 100644
--- a/drivers/gpio/gpio-pch.c
+++ b/drivers/gpio/gpio-pch.c
@@ -394,7 +394,9 @@
 	pci_set_drvdata(pdev, chip);
 	spin_lock_init(&chip->spinlock);
 	pch_gpio_setup(chip);
+#ifdef CONFIG_OF_GPIO
 	chip->gpio.of_node = pdev->dev.of_node;
+#endif
 	ret = gpiochip_add(&chip->gpio);
 	if (ret) {
 		dev_err(&pdev->dev, "PCH gpio: Failed to register GPIO\n");