hal: audio_hw: Allow 50ms sleep if audio start fails before exit

If audio start for output/input fails for some reason, allow 50ms sleep
before exit, so next attempt to start output/input happens after 50ms.
This will facililate kernel drivers not to be flooded with
failure logs and helps in cases like SSR recovery.

Change-Id: I9e214f1d01dc8537c8a7800fb174676d9a6ee5c8