hal_audio: remove access to audiohal_data_file

This is no longer used and violates Treble data separation.

Bug: 68057930
Test: verify on Sailfish that /data/misc/audiohal doesn't exist
    This dir appears to be Qualcomm specific and should not have
    been defined in core policy.

Change-Id: I55fba7564203a7f8a1d8612abd36ec1f89dc869d