gpiod_get/set functions share common code between their regular and
cansleep variants. The exporting of the gpiod interface will make
the situation worse. This patch factorizes the common code to avoid code
redundancy.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>