CONFIG_ARCH_WANT_OPTIONAL_GPIOLIB (not configurable)

configname: CONFIG_ARCH_WANT_OPTIONAL_GPIOLIB

Linux Kernel Configuration
└─>Device Drivers
└─>ARCH_WANT_OPTIONAL_GPIOLIB
In linux kernel since version 2.6.27 (release Date: 2008-10-09)  
Select this config option from the architecture Kconfig, if
it is possible to use gpiolib on the architecture, but let the
user decide whether to actually build it or not.
Select this instead of ARCH_REQUIRE_GPIOLIB, if your architecture does
not depend on GPIOs being available, but rather let the user
decide whether he needs it or not.

is selected by
CONFIG_GPIOLIB