Sun documentation mentions that ZX can not run on a sun4c or inside an xbox, so document this as well.
Sun documentation mentions that ZX can not run on a sun4c or inside an xbox,
so document this as well.

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars