CONFIG_ARCH_EXYNOS is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
SAMSUNG EXYNOS
configname: CONFIG_ARCH_EXYNOS
ARM system type
└─>SAMSUNG EXYNOS
In linux kernel since version 3.1 (release Date: 2011-10-24)
Support for SAMSUNG's EXYNOS SoCs (EXYNOS4/5)