Adding the x86_cpu_id::steppings field is an ABI change. It doesn't
seem worth the trouble of another ABI bump just to be able to report
some potential future CPU steppings as invulnerable. Until we have
other change that require an ABI bump, we'll match the affected models
regardless of stepping.
Keep the reverted patch in the queue so that the reverting patch will
continue to be applied when we rebase onto a new stable update.