audio/msm7630: Fix for back to back VOIP calls failure

- Back to back VOIP calls fail.
- MVS driver is not closed in HAL at the end of VOIP call
  due to wrong book keeping of VOIP in and out streams.
  This prevents back to back VOIP calls.
- Enhance bookkeeping code and close driver at end of VOIP call

(cherry picked from commit 2884ae26b9b65f49acee44a49efbc6196ab6d15f)

Change-Id: I4aa578442c24949b56586a5260fefd5e73c9292a