CONFIG_ARCH_RANDOM is not available for the selected architecture x86.
Result is shown for architecture powerpc

CONFIG_ARCH_RANDOM (not configurable)

modulename: arch_random.ko

configname: CONFIG_ARCH_RANDOM

Linux Kernel Configuration
└─>ARCH_RANDOM
In linux kernel since version 2.6.32.7 (release Date: 2010-01-28)