greybus: connection: handle static connections

Use host-device device and connection name for log messages rather than
assume that all connections have a bundle (e.g. not true for static
connections).

Note that the "initial" svc connection has never had a bundle.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>