configs: msmsteppe_au: add routing for car streams

Update audio policy configuration and mixer paths
to support routing of the car streams to bus devices
for automotive platform.
Add audio HAL maj version 3 for automotive.
Enable auto hal audio, audio control and hw plugin
extension feature flag.

Change-Id: Idf353736b28fe75e0b2ec8bf05e2eff4d2415e94