Add a CUPS option to disable cups support and remove the
dependency on print/cups. This includes a patch from cpm@ that
solves an undefined linker reference that occurs when cups is
disabled. Since chromium does not support printing without cups
enabling this option also disables printing and print previews.

PR: 226505
Reviewed by: cpm, matthew (mentor)
Approved by: cpm, matthew (mentor)
Differential Revision: https://reviews.freebsd.org/D14659