default or selected kernelversion does not have config value CONFIG_CPU_SRSO.
Result is shown for kernelversion 6.9.9

Mitigate speculative RAS overflow on AMD

configname: CONFIG_CPU_SRSO

Linux Kernel Configuration
└─>Mitigations for CPU vulnerabilities
└─>Mitigate speculative RAS overflow on AMD
In linux kernel since version 4.14.326 (release Date: 2023-09-23)  
Enable the SRSO mitigation needed on AMD Zen1-4 machines.