CONFIG_PLAT_S3C24XX is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

CONFIG_PLAT_S3C24XX (not configurable)

configname: CONFIG_PLAT_S3C24XX

Linux Kernel Configuration
└─>PLAT_S3C24XX
In linux kernel since version 2.6.21 (release Date: 2007-04-25)  
Base platform code for any Samsung S3C24XX device


depends
CONFIG_ARCH_S3C2410 or CONFIG_ARCH_S3C24A0