msm: mhi_dev: Fix send completion for channel start

Fix sending completion events for hardware channel start.
Handle error returned from IPA during hardware channel
start and send error for the completion event to host.
Host may stop processing further start commands on not
receiving completion events from the device.

Change-Id: Ifaf92f53eed4832b4a0ba243b6e308aa1434e645
Signed-off-by: Siddartha Mohanadoss <smohanad@codeaurora.org>