CONFIG_S3C2412_IOTIMING is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

CONFIG_S3C2412_IOTIMING (not configurable)

modulename: iotiming-s3c2412.ko

configname: CONFIG_S3C2412_IOTIMING

Linux Kernel Configuration
└─>SAMSUNG S3C24XX SoCs Support
└─>S3C2412_IOTIMING
In linux kernel since version 2.6.32 (release Date: 2009-12-02)  
Intel node to select io timing code that is common to the s3c2412
and the s3c2443.

source code:
arch/arm/mach-s3c24xx/iotiming-s3c2412.c