audio: hal: Fix for DTSHD passthrough playback

-DTSHD passthrough is not working when drift correction is enabled.
-Drift correction enablement calls out_write(0) to start compress
 session. However DTSHD iec61937 transmission info parsing fails due
 to size zero write buffer.
-To fix this added
  -Changes to call dts parser when first valid buffer is enabled.
  -Changes to trigger select_device() to update backend configuration.
-Also added mixer path change to configure default HDMI backend
 configuration

Change-Id: I68b2c79ff008a7d081efa475c8b9782072f5ce03