CONFIG_MACH_LOONGSON32 is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

Loongson-1 family of machines

configname: CONFIG_MACH_LOONGSON32

System type
└─>Loongson-1 family of machines
In linux kernel since version 3.10 (release Date: 2013-06-30)  
This enables support for the Loongson-1 family of machines.

Loongson-1 is a family of 32-bit MIPS-compatible SoCs developed by
the Institute of Computing Technology (ICT), Chinese Academy of
Sciences (CAS).