gpiolib: Remove unused of_mm_gpiochip_add()

of_mm_gpiochip_add() is unused API, remove it for good.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

drivers/gpio/TODO

@@ -61,8 +61,8 @@ Work items:
 
 - Get rid of struct of_mm_gpio_chip altogether: use the generic  MMIO
   GPIO for all current users (see below). Delete struct of_mm_gpio_chip,
-  to_of_mm_gpio_chip(), of_mm_gpiochip_add_data(), of_mm_gpiochip_add()
-  of_mm_gpiochip_remove() from the kernel.
+  to_of_mm_gpio_chip(), of_mm_gpiochip_add_data(), of_mm_gpiochip_remove()
+  from the kernel.
 
 - Change all consumer drivers that #include <linux/of_gpio.h> to
   #include <linux/gpio/consumer.h> and stop doing custom parsing of the

include/linux/of_gpio.h

@@ -56,11 +56,6 @@ extern int of_get_named_gpio(const struct device_node *np,
 extern int of_mm_gpiochip_add_data(struct device_node *np,
 				   struct of_mm_gpio_chip *mm_gc,
 				   void *data);
-static inline int of_mm_gpiochip_add(struct device_node *np,
-				     struct of_mm_gpio_chip *mm_gc)
-{
-	return of_mm_gpiochip_add_data(np, mm_gc, NULL);
-}
 extern void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc);
 
 #else /* CONFIG_OF_GPIO */