CONFIG_CPU_LOONGSON2 is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

Loongson 2

modulename: r4k_fpu.ko

and/or

c-r4k.ko

and/or

dump_tlb.ko

configname: CONFIG_CPU_LOONGSON2

CPU type
└─>Loongson 2
In linux kernel since version 2.6.23 (release Date: 2007-10-09)  
The Loongson 2E processor implements the MIPS III instruction set
with many extensions.

source code:
arch/mips/mm/