CONFIG_XTENSA_VARIANT_S6000 is not available for thedefaultarchitecture x86.
Result is shown for architecture xtensa

s6000 - Stretch software configurable processor

configname: CONFIG_XTENSA_VARIANT_S6000

Xtensa Processor Configuration
└─>s6000 - Stretch software configurable processor
In linux kernel since version 2.6.30 (release Date: 2009-06-09)