process/reg-suit: 1157802: report skip when nr_cpu < 4
Tested on a 2 processors host: (bz1157802 reported as 'SKIP'). https://beaker.engineering.redhat.com/recipes/16072952#task177277273,task177277274
Tested on a 2 processors host: (bz1157802 reported as 'SKIP'). https://beaker.engineering.redhat.com/recipes/16072952#task177277273,task177277274