CONFIG_CPU_R4000_WORKAROUNDS is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

CONFIG_CPU_R4000_WORKAROUNDS (not configurable)

configname: CONFIG_CPU_R4000_WORKAROUNDS

Linux Kernel Configuration
└─>Kernel type
└─>CPU_R4000_WORKAROUNDS
In linux kernel since version 2.6.25 (release Date: 2008-04-16)