Provide example for setting processor affinity (SMP example)

[skliper]

Is your feature request related to a problem? Please describe.
SMP is a hot topic these days, we keep saying it's easy but no example provided showing how one could set a thread's CPU affinity.

Describe the solution you'd like
Provide an example for the "simplest" identified method for assigning threads to cores.

Describe alternatives you've considered
There's numerous approaches, this just shows one that assigns threads when created. One could manage threads from a platform specific app, do power management, fault management, etc.

Additional context
See nasa/osal#210, nasa/cFS#427.

Requester Info
Jacob Hageman - NASA/GSFC