Subject: ASoC: msm: lock read/write when add/free audio ion memory

As read/write get access to ion memory region as well, it's
necessary to lock them when ion memory is about to be added/freed
to avoid racing cases.

Change-Id: Ie4235889c1a290e0d9aa5c96bc635a8053671c89
Signed-off-by: soon9.lee <soon9.lee@samsung.com>