t0lte: reduce mic gain

Change-Id: I001b82b1b22213b5f775b0e2667c575d679bc52a
t0lte: user configurable voice index

This uses 4 files to store the voice index for each device,
incall_headset, incall_headphone, incall_speaker, incall_bt, all
located /data/t0lte_audio. Higher index = Increased volume.

If an index is changed while incall, the device must be toggled
(headset -> speaker -> headset).

Change-Id: I4269dc65d48e04b5e908b20704128241683d5a80

Conflicts:
	DeviceSettings/src/com/cyanogenmod/settings/device/Startup.java
	audio/audio_hw.c