gpiolib: acpi: Move acpi_gpio_to_gpiod_flags() upper in the code

Move acpi_gpio_to_gpiod_flags() upper in the code to allow further refactoring.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>