reduce number of binder calls from mediaserver

Reduce the number of audio port, audio patch and
IO config changed binder calls from mediaserver to
client processes:
- Do not call IO config changed callback if selected
device is the same as previously selected one on a given
audio flinger playback or capture thread.
- Do not call the audio port or audo patch list update
callback on a client if this client as no listener registered.

Bug: 22045560.

Change-Id: If780e105404de79b7cb5c80c27b793ceb6b1c423