CONFIG_MACH_LOONGSON64 is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

Loongson-2/3 family of machines

modulename: cop2-ex.ko

configname: CONFIG_MACH_LOONGSON64

System type
└─>Loongson-2/3 family of machines
In linux kernel since version 3.10 (release Date: 2013-06-30)  
This enables the support of Loongson-2/3 family of machines.

Loongson-2 is a family of single-core CPUs and Loongson-3 is a
family of multi-core CPUs. They are both 64-bit general-purpose
MIPS-compatible CPUs. Loongson-2/3 are developed by the Institute
of Computing Technology (ICT), Chinese Academy of Sciences (CAS)
in the People's Republic of China. The chief architect is Professor
Weiwu Hu.