CONFIG_CEVT_CSRC_LS1X is not available for thedefaultarchitecture x86.
Result is shown for architecture mips
default or selected kernelversion does not have config value CONFIG_CEVT_CSRC_LS1X.
Result is shown for kernelversion 6.9.9

Use PWM Timer for clockevent/clocksource

configname: CONFIG_CEVT_CSRC_LS1X

Linux Kernel Configuration
└─>Use PWM Timer for clockevent/clocksource
In linux kernel since version 3.10 (release Date: 2013-06-30)  
This option changes the default clockevent/clocksource to PWM Timer,
and is required by Loongson1 CPUFreq support.

If unsure, say N.