Convert gl2ps to CMakePackage (#3360)
Convert gl2ps to CMakePackage (#3360)

* Convert gl2ps to CMakePackage

* Remove unused spec variable

mfherbst/spack,TheTimmy/spack,mfherbst/spack,iulian787/spack,lgarren/spack,TheTimmy/spack,mfherbst/spack,LLNL/spack,skosukhin/spack,iulian787/spack,tmerrick1/spack,EmreAtes/spack,lgarren/spack,skosukhin/spack,krafczyk/spack,EmreAtes/spack,tmerrick1/spack,skosukhin/spack,TheTimmy/spack,EmreAtes/spack,lgarren/spack,LLNL/spack,TheTimmy/spack,matthiasdiener/spack,mfherbst/spack,tmerrick1/spack,iulian787/spack,EmreAtes/spack,EmreAtes/spack,krafczyk/spack,mfherbst/spack,matthiasdiener/spack,iulian787/spack,LLNL/spack,tmerrick1/spack,iulian787/spack,LLNL/spack,lgarren/spack,matthiasdiener/spack,krafczyk/spack,matthiasdiener/spack,matthiasdiener/spack,lgarren/spack,krafczyk/spack,krafczyk/spack,skosukhin/spack,LLNL/spack,tmerrick1/spack,skosukhin/spack,TheTimmy/spack