[REBASED on main (r3branch)from r2-stable branch]ASoC:dapm-Add DAPM stream completion...

[REBASED on main (r3branch)from r2-stable branch]ASoC:dapm-Add DAPM stream completion event

BZ: 17975

This adds a callback function to be called at the completion of a
DAPM stream event.

This can be used by codec to perform operation based on
DAPM graphs  after completion of stream events.

This work is adopted from the upstream asoc kernel.

rebasing it to r3 -- Main branch.

Change-Id: I6b89f5a55f04a508ae27131dfe0357c4134ad11c
Old-Change-Id: I138dc0cb1ab90495c96312a7e54f234a48320c9f
Reviewed-on: http://android.intel.com:8080/29544
Reviewed-by: M, Arulselvan <arulselvan.m@intel.com>
Tested-by: M, Arulselvan <arulselvan.m@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>