Adopting GPU Params change from WMCore

[novicecpp]

Adopting Alan's PR here dmwm/WMCore#11689
Original issue: dmwm/WMCore#11595
SI ticket: https://its.cern.ch/jira/browse/CMSSI-79

We already supported GPU params in CRAB #7470
We only need to change how construct classads attribute same way WMCore do.

Waiting until SI ticket and Alan's PR are closed.