greybus: svc: No need of per-direction route-create requests

The route-create request creates bi-directional routes and there is no
need to make separate calls for setting up routes on both the
directions.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>