msm: bam_dmux: add delay to msm9615 bam initialization

Add a delay to the msm9615 bam initialization to avoid a race condition.
When A2 signals that it is ready, it has not yet enabled the BAM hardware
which would cause an initialization failure depending on how fast apps is
and prevent embedded data calls from being established.

Change-Id: I4b788128393ef87b0015d11eeb8c28e4be985102
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>
Signed-off-by: Eric Holmberg <eholmber@codeaurora.org>