CONFIG_S3C24XX_SMDK is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

CONFIG_S3C24XX_SMDK (not configurable)

configname: CONFIG_S3C24XX_SMDK

Linux Kernel Configuration
└─>Samsung S3C24XX SoCs Support
└─>S3C24XX_SMDK
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Common machine code for SMDK2410 and SMDK2440