CONFIG_RISCV_ISA_VENDOR_EXT is not available for the selected architecture x86.
Result is shown for architecture riscv
CONFIG_RISCV_ISA_VENDOR_EXT (not configurable)
configname: CONFIG_RISCV_ISA_VENDOR_EXT
Linux Kernel Configuration
└─>Vendor extensions
└─>RISCV_ISA_VENDOR_EXT