hal: add bus stream for front passenger zone

Add bus stream for front passenger zone playback
on automotive platform.

Primary zone         -> Mercury
Front passenger zone -> A2B1 (8CH DAC1) (ALL)
Rear seat zone       -> A2B2 (16CH DAC1&2) (SA81x5)
                        A2B1 (8CH DAC2) (SA6155)

Change-Id: Ib288f84c94d33f2f49d45b32d6810e0b91db967f