msm: audio: qdsp6v2: Change ASM cmd sequence

- Memory map failure observed while music playback.
- Audio driver issuing memory unmap cmd first then issuing
  ASM_CMD_CLOSE, due to which memory map failure observed.
- Issue unnmap cmd after receiving the ack for ASM_CMD_CLOSE.

Change-Id: Ic6dd9775b0aea218874161b8a44dc0286608616c
Signed-off-by: Deepa Madiregama <dmadireg@codeaurora.org>