Drop dependency on atomic from all platforms.
    
    We cannot have inconsistent requires amongs the architectures. Otherwise
    the koji build fails with:
    
       BuildError: mismatch when analyzing
       openscap-containers-1.2.6-2.fc24.noarch.rpm, rpmdiff output was:
       error: cannot open Packages index using db5 - Permission denied (13)
       error: cannot open Packages database in /var/lib/rpm
       error: cannot open Packages database in /var/lib/rpm
       added       REQUIRES atomic