audio: provide a hook for audio amplifier implementations

Example: http://review.cyanogenmod.org/#/c/38221

Change-Id: Ib236598a5888b2af19bcfb81e285f644a0e84c0d
msm8660: Fix VoIP device for Samsung Audio

* Add USE_SAMSUNG_VOIP_DEVICE for voip devices
* Added ifdef for MVS include

Change-Id: I57b52cc159eb6ef5cadadf8acacffceaf2bc77aa
msm8660: Fix call/voip audio routing for Samsung audio

Change-Id: I021344b1c4672b2fb92503059b3eaec6121bdc19
alsa_sound: Add support for seperated VOIP devices

 * Similar to the VOC devices tuned for voice calls, some new devices
   are using VOIP devices tuned for SIP and Hangouts.
 * Enable with BOARD_USES_SEPERATED_VOIP

Change-Id: I3a49be26ca2ad3e1aafb8b0960935ac8c735fe51
alsa_sound: Add support for seperated headset mic devices

 * Some recent devices such as the Galaxy S4 use dedicated 3-pole
 * headset mic devices while in-call.
 * This also supports the seperated VOIP headset mic device.
 * Only engage the ES325 dualmic for speaker/earpiece usecases.

Change-Id: I1c0b01a9df70fbb7364ba69004aa7828e3f1f01c
alsa_sound: Add support for VR-on-wired-headset device

Change-Id: Ib206649194794f46480b7f87eaeb9e3fdb0df1b1
Merge "audio: provide a hook for audio amplifier implementations" into cm-10.1