gpio: add parameter to allow the use named gpios

The gpio binding document says that new code should always use named
gpios. Patch 40b73183 added support to parse a list of gpios from child
nodes, but does not make it possible to use named gpios. This patch adds
the con_id property and implements it is done in gpiolib.c, where the
old-style of using unnamed gpios still works.

Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
Acked-by: Bryan Wu <cooloney@gmail.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/drivers/input/keyboard/gpio_keys_polled.c b/drivers/input/keyboard/gpio_keys_polled.c
index 90df4df..097d721 100644
--- a/drivers/input/keyboard/gpio_keys_polled.c
+++ b/drivers/input/keyboard/gpio_keys_polled.c
@@ -125,7 +125,7 @@
 	device_for_each_child_node(dev, child) {
 		struct gpio_desc *desc;
 
-		desc = devm_get_gpiod_from_child(dev, child);
+		desc = devm_get_gpiod_from_child(dev, NULL, child);
 		if (IS_ERR(desc)) {
 			error = PTR_ERR(desc);
 			if (error != -EPROBE_DEFER)