CONFIG_CPU_FR451 is not available for the selected architecture x86.
Result is shown for architecture frv
Include FR451 core support
configname: CONFIG_CPU_FR451
Linux Kernel Configuration
└─>Fujitsu FR-V system setup
└─>CPU core support
└─>Include FR451 core support
In linux kernel since version 2.6.12 )
This enables support for the FR451 CPU