m-si-audio-adapter: make sure format task is finished even if ports were already configured

Currently, if the adapter node already has its ports configured when wireplumber starts (For example a virtual node), the async _set_ports_format() call is never completed because the node ports have not changed, stalling the event stack. This patch fixes the issue by checking the Props param after configuring the ports, and completes the task if there is one pending and the node already has ports available.

Fixes #527 (closed)