CONFIG_ARCH_S3C2440 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

SMDK2440

modulename: mach-smdk2440.ko

configname: CONFIG_ARCH_S3C2440

Linux Kernel Configuration
└─>Samsung S3C24XX SoCs Support
└─>SMDK2440
In linux kernel since version 2.6.12  
Say Y here if you are using the SMDK2440.