[yocto] Force recipe to provide specific file

[Stath, Paul]

> >   why not just provide a .bbappend file and an overriding file?
> 
> Do you mean that I should integrate my version of the files into the
> ghostscript package?
> This is what I want to avoid because all cups-filters should reside in the
> cups-filters package.
> 

It is not necessarily true that all cups-filter programs should reside in the cups-filters package.
Remember that the CUPS system expects a PostScript printer, and the filters in the cups-filters
package filter (or convert) non-PostScript input to PostScript.

The ghostscipt package is a PostScript interpreter that is capable of taking a PostScript
input file and producing output in several different formats.
Since the ghostscript package creates filters that convert files from PostScript
to a different format, both the gstopxl and gstoraster filter programs require the
ghostscript interpreter package for them to execute properly.
Note that the ghostscript recipe lists 'cups' in the DEPENDS.

A system where the cups* packages are installed, but the ghostscript package
is not can still print to a printer capable of accepting PostScript print jobs.
Such a system would not be able to print to a PCL or dot-matrix printers however.