This will help removing the GENERIC_GPIO option.

GPIO access is done through gpiolib, which selects GENERIC_GPIO anyway.
Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>