gpio: propagate of_parse_phandle_with_args errors

Make of_get_named_gpio_flags propagate any error it receives from
of_parse_phandle_with_args instead of inconditionally returning -EINVAL.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 8389d4a..a71aeca 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -73,7 +73,7 @@
 					 &gg_data.gpiospec);
 	if (ret) {
 		pr_debug("%s: can't parse gpios property\n", __func__);
-		return -EINVAL;
+		return ret;
 	}
 
 	gpiochip_find(&gg_data, of_gpiochip_find_and_xlate);