limit GOMAXPROCS in Talos Go processes

[smira]

Having high GOMAXPROCS (e.g. on 32+ on multi-core systems) might be a source of inefficiency for processes using less than maximum number of cores.

Talos's machined, apid, trustd should not ever use more than 2-4 cores in any real-life scenario.

So the proposal is to set runtime.Numprocs to the value:

• machined: max(numcpus, 4)
• apid: max(numcpus, 2)
• trustd: max(numcpus, 2)