ipc: apr: Fix apr buffer override issue

Need use one global lock to prevent multiple threads visit single hab
socket at same time, as hab can't guarantee that the coming message is
received by the right thread.

Change-Id: Ie63a48cd9518327c9e4078000e613767ee1321b5
Signed-off-by: Narsinga Rao Chella <nrchella@codeaurora.org>