Remove the dep on cpuinfo parser int he process.py

[iphands]

I was looking at https://github.com/RedHatInsights/insights-puptoo/pull/55/files#diff-2759c7155304e3e2ebd22fc510b19405

I think that we could kill the dep on the cpuinfo parser entirely here:
https://github.com/RedHatInsights/insights-puptoo/blob/master/src/puptoo/process.py#L114

And just use lscpu for all.
Seems like a reasonable thing to do eh?