hammerhead: Add Qualcomm MSM Audio devices to sepolicy

Change-Id: I3402ec861215624512a27bd4ccbd134143493b79
hammerhead: Update mixer paths and platform info

* Add mixer path for stereo handset, this fixes usecases
  like WhatsApp voice messaging.
* Add new dual-mic path and use for camcorder-mic and
  handset-stereo-dmic-ef
* Add platform info mappings

Change-Id: I346a6cc001729fb1061c9303f72109a04d3d2b30