P5110: Add audio.r_submix.default for casting

Change-Id: Ie39b01c9eefe690b1debec24e8b74b826ede9b13
P51XX: add "AUDIO_DEVICE_OUT_EARPIECE" to audio_policy.conf

Change-Id: Ia9a30986ee78679ef0adeee077258dd9cfc3f47b