gpio: Export gpiod_get_from_of_node()

This function already exist inside gpiolib, we were just
reluctant to make it available to the kernel at large as
the devm_* seemed to be enough for anyone.

However we found out that regulators need to do their own
lifecycle/refcounting on GPIO descriptors and explicitly
call gpiod_put() when done with a descriptor, so export
this function so we can hand the refcounting over to the
regulator core for these descriptors after retrieveal.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/gpio/gpiolib.h

@@ -201,12 +201,6 @@ int gpiod_set_array_value_complex(bool raw, bool can_sleep,
 				  struct gpio_array *array_info,
 				  unsigned long *value_bitmap);
 
-/* This is just passed between gpiolib and devres */
-struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
-					 const char *propname, int index,
-					 enum gpiod_flags dflags,
-					 const char *label);
-
 extern struct spinlock gpio_lock;
 extern struct list_head gpio_devices;