cad-pulse: filter card based on available ports

The card name and main attributes aren't always enough to properly identify the proper card to use. For example, the HDMI audio output on PP is named platform-hdmi-sound, and is sometimes picked up as the main card even though it's obviously wrong.

With this commit, only the cards having both a Speaker and a Earpiece ports will be considered, which should solve most of the remaining problems.

We also setup a retry timer in case no suitable card is found in an attempt to fix #18 (closed).