hammerhead: Set permissions for MDP idle notifier

Change-Id: Ibe2cbccd533437cf9a2ccedc4b634c4ea8b04850
hammerhead: Update mixer paths and audio platform

Add mixer path for stereo handset, this fixes usecases like
WhatsApp voice messaging.

Add basic audio platform mappings, disable noise suppression
for camcorder recording to improve sound quality.

Change-Id: I346a6cc001729fb1061c9303f72109a04d3d2b30
hammerhead: Update ueventd rules

Change-Id: If8787468112adcdebb8c53a81c204d085bc7d06f
hammerhead: Enable aac hardware encoder

We support RAW streams now.

Change-Id: I6e89562012f817ed582259eaea4e6a77d89eee83