msm: mhi_dev: Generalize uevents to apply for all MHI clients

Channel state updates are sent via uevents to MHI clients. The
channel attribute table specifies which clients need to be
notified.

Change-Id: I80afa8baa0bafab36851dfcaea6c86fd8a1a8e71
Signed-off-by: Siva Kumar Akkireddi <sivaa@codeaurora.org>