net: Add Neuron Framework

Neuron is a device-sharing framework which is used by guests of the
haven hypervisor to serve or access shared I/O devices and other
inter-VM services.

There are three main layers that make up a neuron service.
channel - the physical layer transport that uses the hypervisor
          provided transports.

protocol - defines the syntax and semantics to virtualize a specific
           device across VMs. Block and Net are examples of protocols.

application - integrates the neuron service components into the rest of
              the system. There would be front and back end application
              drivers for the net protocol.

Change-Id: Ic7278fdaee1cd30147e91e1126643bce79c05e52
Signed-off-by: Chris Lew <clew@codeaurora.org>