It makes sense for a GPIO driver to want to get its own descriptor
without requesting it. After all, the driver knows that it'll still be
valid. Let's move this helper to linux/gpio/driver.h.
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>