ASoC: msm: qdsp6v2: Avoid double free of hw_delay structure

acdb_release function can be called from multiple threads resulting
in double free of hw_delay structure. Avoid this by freeing it only
when usage count is 1.

Change-Id: Id10d095b03dc8ec9554b2a91f2e387838c585a0b
CRs-fixed: 555760
Signed-off-by: Pradnya Chaphekar <pradnyac@codeaurora.org>