CONFIG_SOC_EXYNOS5250 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Samsung Exynos5250

modulename: clk-exynos5250.ko

and/or

clk-exynos5-subcmu.ko

configname: CONFIG_SOC_EXYNOS5250

Linux Kernel Configuration
└─>Samsung Exynos
└─>Samsung Exynos5250
In linux kernel since version 3.1 (release Date: 2011-10-24)