manuals/description: system video console utilitys

Update the man page descriptions so that apropos are more consistent for
console related man pages.

Motive: apropos results: clarify consistently
MFC after: 3 days
Reviewed by: emaste, imp
Pull Request: https://github.com/freebsd/freebsd-src/pull/1275

(cherry picked from commit de2ab11ff955faa32bfffe5b2401b444a7c138f2)