gpiolib: Do not mention legacy GPIOF_* in the code

We are going to remove legacy API from kernel, don't mention
it in the code that does not use it already for a while.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Author: andy-shev

drivers/gpio/gpiolib.c

@@ -365,7 +365,10 @@ int gpiod_get_direction(struct gpio_desc *desc)
 	if (ret < 0)
 		return ret;
 
-	/* GPIOF_DIR_IN or other positive, otherwise GPIOF_DIR_OUT */
+	/*
+	 * GPIO_LINE_DIRECTION_IN or other positive,
+	 * otherwise GPIO_LINE_DIRECTION_OUT.
+	 */
 	if (ret > 0)
 		ret = 1;