hal: fix bt sco and a2dp concurrency issues

When sco mic device is already active and
SND_DEVICE_OUT_BT_A2DP is enabled, then route
is switched to A2dp, but sco mic can still
keep active which means the BE is already
active, causing the slimbus configuration of
feedback path for A2dp to be ignored.
To fix this, tear down the input stream to
disable bt sco mic before enabling a2dp path.

Change-Id: I42e37e7b192d374401406cfa6dff4b97dca36697