CONFIG_S3C2440_XTAL_12000000 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_S3C2440_XTAL_12000000.
Result is shown for kernelversion 6.9.9

CONFIG_S3C2440_XTAL_12000000 (not configurable)

configname: CONFIG_S3C2440_XTAL_12000000

Linux Kernel Configuration
└─>Samsung S3C24XX SoCs (deprecated, see help)
└─>Samsung S3C24XX SoCs Support
└─>S3C2440_XTAL_12000000
In linux kernel since version 2.6.32 (release Date: 2009-12-02)  
Indicate that the build needs to support 12MHz system
crystal.