The sysfs ABI to GPIO is marked obsolete and should not be
encouraged. Users should be encouraged to switch to using the
character device.

Let's begin by removing it from the multi defconfigs. Then
as time goes by I can aggressively remove it from other
defconfigs.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>