ASoC: msm: qdsp6v2: update default channel mapping

- Update default 5.1 and 7.1 channel mapping in q6adm.c
  for compress offload multi-channel playback.
- Update default 5.1 and 7.1 channel mapping in q6asm.c
  for PCM format multi-channel playback.
- Channel mapping can be overwritten by mixer controls
  passed from user space/HAL.

CRs-Fixed: 582601
Change-Id: I168277f08790773411b7965784143318f72df64b
Signed-off-by: Mingming Yin <mingming@codeaurora.org>