msm: mhi_dev: Update notification on channel state

Update channel state notification broadcast to software channels
only as there are no clients listening to the broadcast for the
HW channel state updates. State updates include channel start,
stop and reset commands.

Change-Id: Ic378acf4a7afc80b7c9e7acdfbf822608983a427
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>