CONFIG_MACH_SMDK2443 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
SMDK2443
modulename: mach-smdk2443.ko
configname: CONFIG_MACH_SMDK2443
Linux Kernel Configuration
└─>S3C2443 Machines
└─>SMDK2443
In linux kernel since version 2.6.21 (release Date: 2007-04-25)
Say Y here if you are using an SMDK2443