Revert "Revert "Remove legacy display flags (@paulb-nl)""

This reverts commit 9301d1539b9698c308e42349a58813b91e3ba60d.
enable BOARD_USES_LEGACY_ALSA_AUDIO

Change-Id: I8a9e50cd67aaddecd30505b105a89dbc2392f441
Use audio-caf

Change-Id: Ib36407b0054965608084f4ea93758de466d94bc7