soc: xtensa: cavstool server support specifying the port and iface

Make the cavstool service can start with specifying the port
optionally by:

   cavstool.py -s {host}:{log port} --req-port {req port}
OR
   cavstool.py -s {host} --log-port {log port} --req-port {req port}

And we can also specify the network interface instead:

   cavstool.py -i {network iface}

If the server address or the network interface is not specified,
it will use INADDR_ANY by default.

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