mhi_bus: core: Call the remove cb before checking channel is closed

During mhi_driver_remove(), MHI waits for channel to be closed. This wait
happens before calling remove() callback, remove() callback allows client
to clean up and close the channel (for example client can call
mhi_unprepare_from_transfer()). Due to this behavior of MHI, client is
clueless and continues holding the channel. This could make MHI wait
forever and hang the system.

Change-Id: I950eedbdb6939bd0d9f70e7fed14afc777571485
Signed-off-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@quicinc.com>