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