Audio: fix voip calls over bluetooth headset.

Current HAL start/stop bt_sco session only for incall mode -
rewrite logic to start/stop bt session when system switch to
one of the bluetooth devices.
Move bt_sco_active and pcm_sco_rx/tx to main audio_device structure.
Remove bt_sco_capture profile.

Change-Id: I7bbe4273f759e255bb857f8292f2921df31d4b0b
Signed-off-by: stenkinevgeniy <stenkinevgeniy@gmail.com>