CONFIG_476_CPU is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc

476 (47x family)

configname: CONFIG_476_CPU

CPU selection
└─>476 (47x family)
In linux kernel since version 6 (release Date: 2022-10-02)  
depends
CONFIG_PPC_47x
NOT CONFIG_CC_IS_CLANG