Introduce gpio_device_get() and gpio_device_put() helpers
and convert existing users.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NBartosz Golaszewski <bartosz.golaszewski@linaro.org>