gpio / ACPI: return -ENOENT when no mapping exists
gpio / ACPI: return -ENOENT when no mapping exists

Doing this allows drivers to distinguish between a real error case (if
there was an error when we tried to resolve the GPIO) and when the optional
GPIO line was not available.

Signed-off-by: Mika Westerberg <afb75201fb002d7fdd2b0b231e006999e00db8a9@linux.intel.com>
Acked-by: Alexandre Courbot <301cd6a3ea50a894b4b51e385c5eb12b9a4ffc0c@nvidia.com>
Acked-by: Rafael J. Wysocki <27ffc44a8ec6a212fba98cfc3246c6ce8ab131e0@intel.com>
Signed-off-by: Linus Walleij <9cd9d802d23c0ed5e224beabf4ae4a5c478746ef@linaro.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs