CONFIG_SOC_EXYNOS4212 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
SAMSUNG EXYNOS4212
configname: CONFIG_SOC_EXYNOS4212
Linux Kernel Configuration
└─>SAMSUNG EXYNOS SoCs Support
└─>SAMSUNG EXYNOS4212
In linux kernel since version 3.1 (release Date: 2011-10-24)
Enable EXYNOS4212 SoC support