CONFIG_ARCH_EXYNOS7 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm64
default or selected kernelversion does not have config value CONFIG_ARCH_EXYNOS7.
Result is shown for kernelversion 5.4.229

ARMv8 based Samsung Exynos7

modulename: clk-exynos7.ko

configname: CONFIG_ARCH_EXYNOS7

Linux Kernel Configuration
└─>Platform selection
└─>ARMv8 based Samsung Exynos7
In linux kernel since version 4 (release Date: 2015-04-12)  
This enables support for Samsung Exynos7 SoC family

source code:
drivers/clk/samsung/clk-exynos7.c