CONFIG_CPU_LOONGSON32 is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

Loongson 32-bit CPU

configname: CONFIG_CPU_LOONGSON32

CPU type
└─>Loongson 32-bit CPU
In linux kernel since version 4.14.326 (release Date: 2023-09-23)  
The Loongson GS232 microarchitecture implements the MIPS32 Release 1
instruction set and part of the MIPS32 Release 2 instruction set.