gpiolib: Warn on drivers still using static gpiobase allocation

In the preparation of getting completely rid of static gpiobase
allocation in the future, emit a warning in drivers still doing so.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

drivers/gpio/gpiolib.c

@@ -715,6 +715,9 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
 		 * a poison instead.
 		 */
 		gc->base = base;
+	} else {
+		dev_warn(&gdev->dev,
+			 "Static allocation of GPIO base is deprecated, use dynamic allocation.\n");
 	}
 	gdev->base = base;