CONFIG_S5P_GPIO_CFG_S5PC1XX is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

CONFIG_S5P_GPIO_CFG_S5PC1XX (not configurable)

modulename: gpio-config.ko

configname: CONFIG_S5P_GPIO_CFG_S5PC1XX

Linux Kernel Configuration
└─>S5P_GPIO_CFG_S5PC1XX
In linux kernel since version 2.6.33 (release Date: 2010-02-24)  
Internal configuration to enable S5PC1XX style GPIO configuration
functions.

source code:
depends
CONFIG_PLAT_S3C

is depended by
CONFIG_PLAT_S5PC1XX