CONFIG_CPU_FR451_COMPILE is not available for thedefaultarchitecture x86.
Result is shown for architecture frv
default or selected kernelversion does not have config value CONFIG_CPU_FR451_COMPILE.
Result is shown for kernelversion 6.7-rc3

Specifically compile for FR451 core

configname: CONFIG_CPU_FR451_COMPILE

Linux Kernel Configuration
└─>Fujitsu FR-V system setup
└─>CPU core support
└─>Specifically compile for FR451 core
In linux kernel since version 2.6.12  
This causes appropriate flags to be passed to the compiler to
optimise for the FR451 CPU