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

SMDKC210

modulename: mach-smdkc210.ko

configname: CONFIG_MACH_SMDKC210

Linux Kernel Configuration
└─>S5PC210 Machines
└─>SMDKC210
In linux kernel since version 2.6.37 (release Date: 2011-01-04)  
Machine support for Samsung SMDKC210
S5PC210(MCP) is one of package option of S5PV310

source code:
arch/arm/mach-s5pv310/mach-smdkc210.c