Samples: Add SMP Pi

This sample showcases efficient utilization of SMP system
with processing of independent resource-hungry workloads.

With no cross-dependencies between workers and no usage of shared
resources (during heavy-lifting itself) we may demonstrate almost
linear scaling of efficiency. I.e. 2 cores do the same amount of
calculations twice faster than only 1 core. 4 cores complete
the same calculations 2 times faster than 2 cores.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>