msm: mhi_dev: Skip mhi channel state info change

Fix Null pointer access when host rescans the device
by not changing the channel state info if channel is
already in disconnected or configured state.

Change-Id: I5e897d7694f958e2b9613abfd23cbc0e975e81a3
Signed-off-by: Ajay Prathi <aprathi@codeaurora.org>