CONFIG_ARM64_ERRATUM_2645198 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm64

Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption

configname: CONFIG_ARM64_ERRATUM_2645198

Linux Kernel Configuration
└─>Kernel Features
└─>ARM errata workarounds via the alternatives framework
└─>Cortex-A715: 2645198: Workaround possible [ESR|FAR]_ELx corruption
In linux kernel since version 6.2 (release Date: 2023-02-19)  
This option adds the workaround for ARM Cortex-A715 erratum 2645198.

If a Cortex-A715 cpu sees a page mapping permissions change from executable
to non-executable, it may corrupt the ESR_ELx and FAR_ELx registers on the
next instruction abort caused by permission fault.

Only user-space does executable to non-executable permission transition via
mprotect() system call. Workaround the problem by doing a break-before-make
TLB invalidation, for all changes to executable user space mappings.

If unsure, say Y.