Remove last references to hardware/audio.h

DeviceHalInterface transitioned to "capabilities" model
(similar to the one already used by streams, e.g. 'supportsDrain').
No direct checking of the HAL version is needed.

AudioPolicy uses its own version read from the configuration,
and these values never checked against the actual HAL version,
thus it does not need versions and macroses from hardware/*.

Test: make & run on N6P
Change-Id: Ic4a56bfa19a9a61edac2b9f9a163fd8f63a0ff87