gpio/gpio-tps65910: gpio_chip.of_node referenced without CONFIG_OF_GPIO defined

commit 626f9914 added code to initialize gpio_chip.of_node, but if
CONFIG_OF_GPIO is not defined gps-tps65910 fails to build with an
error complaining gpio_chip has no member of_node. I ran into this
while doing a allyesconfig build on linux-next.
Signed-off-by: Gerard Snitselaar <dev@snitselaar.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-tps65910.c

@@ -149,7 +149,9 @@ static int __devinit tps65910_gpio_probe(struct platform_device *pdev)
 	tps65910_gpio->gpio_chip.set	= tps65910_gpio_set;
 	tps65910_gpio->gpio_chip.get	= tps65910_gpio_get;
 	tps65910_gpio->gpio_chip.dev = &pdev->dev;
+#ifdef CONFIG_OF_GPIO
 	tps65910_gpio->gpio_chip.of_node = tps65910->dev->of_node;
+#endif
 	if (pdata && pdata->gpio_base)
 		tps65910_gpio->gpio_chip.base = pdata->gpio_base;
 	else