i9300: Add missing device-specific variables

Change-Id: I5117ee0ed6ddda6f246a8ecf5425e4f9f5992245
i9300: audio: update hal

Brings the audio in line with i9305, n7100, n7105

Fixes various issues.
Only bug left now is audio stutter in real racing 3
which is probably due to the lovely hwcomposer.

Change-Id: I67b0df685e4175b248d2f75608c47cb2bfe85527