CONFIG_ARM64_WORKAROUND_SPECULATIVE_SSBS is not available for thedefaultarchitecture x86.
Result is shown for architecture arm64

CONFIG_ARM64_WORKAROUND_SPECULATIVE_SSBS (not configurable)

configname: CONFIG_ARM64_WORKAROUND_SPECULATIVE_SSBS

Linux Kernel Configuration
└─>Kernel Features
└─>ARM errata workarounds via the alternatives framework
└─>ARM64_WORKAROUND_SPECULATIVE_SSBS
In linux kernel since version 4.19.318 (release Date: 2024-07-18)