Async callback queue updates, applied to XAStreamInformationItf

Async callback queue updates, applied to XAStreamInformationItf

Updated the asynchronous callback queue system to support 'piipp'
 callback signatures.

Applied this update to make the StreamInformation property change
 event notification asynchronous.

Made the XA_PLAYEVENT_HEADATEND also use the callback queue.

Change-Id: I6fd8dee5eefa1d09006661f69de302a8b7fff0f5