audio: msm8660: Update references to AUDIO_FORMAT

* We should use AUDIO_FORMAT_XXXXX instead of AudioSystem::XXXXX
  definitions.

Change-Id: Idb56bc07f8950cb2f1280f4e0db87fd494782c34
audio-caf: fix build when QCOM_USBAUDIO_ENABLED = false

Change-Id: I18ef8967d540c7104c465ddcc5ff19dbcbbdd2bd