CONFIG_CPU_S3C2412 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

CONFIG_CPU_S3C2412 (not configurable)

modulename: s3c2412.ko

and/or

s3c2412-irq.ko

and/or

s3c2412-clock.ko

configname: CONFIG_CPU_S3C2412

Linux Kernel Configuration
└─>CPU_S3C2412
In linux kernel since version 2.6.18 (release Date: 2006-09-19)  
Support for the S3C2412 and S3C2413 SoCs from the S3C24XX line

source code:
arch/arm/mach-s3c2410/s3c2412.c


is selected by
CONFIG_CPU_ARM926T