gpiolib: Add missing dummies for the unified device properties interface

If GPIOLIB=n:

    drivers/leds/leds-gpio.c: In function ‘gpio_leds_create’:
    drivers/leds/leds-gpio.c:187: error: implicit declaration of function ‘devm_get_gpiod_from_child’
    drivers/leds/leds-gpio.c:187: warning: assignment makes pointer from integer without a cast

Add dummies for fwnode_get_named_gpiod() and devm_get_gpiod_from_child()
for the !GPIOLIB case to fix this.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Fixes: 40b73183 ("gpio: Support for unified device properties interface")
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bryan Wu <cooloney@gmail.com>

include/linux/gpio/consumer.h

@@ -406,6 +406,21 @@ static inline int desc_to_gpio(const struct gpio_desc *desc)
 	return -EINVAL;
 }
 
+/* Child properties interface */
+struct fwnode_handle;
+
+static inline struct gpio_desc *fwnode_get_named_gpiod(
+	struct fwnode_handle *fwnode, const char *propname)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
+static inline struct gpio_desc *devm_get_gpiod_from_child(
+	struct device *dev, const char *con_id, struct fwnode_handle *child)
+{
+	return ERR_PTR(-ENOSYS);
+}
+
 #endif /* CONFIG_GPIOLIB */
 
 /*