CONFIG_S3C_DEV_NAND is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

CONFIG_S3C_DEV_NAND (not configurable)

modulename: dev-nand.ko

configname: CONFIG_S3C_DEV_NAND

Linux Kernel Configuration
└─>S3C_DEV_NAND
In linux kernel since version 2.6.32 (release Date: 2009-12-02)  
Compile in platform device definition for NAND controller

source code:
arch/arm/plat-s3c/dev-nand.c