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

CONFIG_PPC_FPU_REGS (not configurable)

configname: CONFIG_PPC_FPU_REGS

Linux Kernel Configuration
└─>Processor support
└─>PPC_FPU_REGS
In linux kernel since version 5.2 (release Date: 2019-07-07)  
is depended by
CONFIG_MATH_EMULATION