soc: intel_adsp: add a client-server based cavstool tool

The cavstool_client.py is a client use to communicate with
the firmware loading and running server which dealing with
the requests from the intel_adsp west runner. It supports:

1. Download firmware to remote ADSP host and running.
2. Send the ADSP log messages back to client.

Signed-off-by: Enjia Mai <enjia.mai@intel.com>