CONFIG_MACH_SMDKC210 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

SMDKC210

modulename: mach-smdkv310.ko

and/or

mach-smdkc210.ko

configname: CONFIG_MACH_SMDKC210

Linux Kernel Configuration
└─>EXYNOS4 Machines
└─>SMDKC210
In linux kernel since version 2.6.37 (release Date: 2011-01-04)  
Machine support for Samsung SMDKC210

source code:
arch/arm/mach-exynos4/mach-smdkc210.c

depends
CONFIG_ARCH_EXYNOS4 |
| CONFIG_EXYNOS_ATAGS