CONFIG_CPU_LOONGSON1 is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

CONFIG_CPU_LOONGSON1 (not configurable)

configname: CONFIG_CPU_LOONGSON1

Linux Kernel Configuration
└─>CPU selection
└─>CPU_LOONGSON1
In linux kernel since version 3.1 (release Date: 2011-10-24)