CONFIG_CPU_EXYNOS4210 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

SAMSUNG EXYNOS4210

modulename: clock-exynos4210.ko

configname: CONFIG_CPU_EXYNOS4210

Linux Kernel Configuration
└─>SAMSUNG EXYNOS SoCs Support
└─>SAMSUNG EXYNOS4210
In linux kernel since version 2.6.39 (release Date: 2011-05-18)  
Enable EXYNOS4210 CPU support

source code:
arch/arm/mach-exynos/clock-exynos4210.c