usb: dwc3-msm: Update DBM event buffer upon ep queue

DBM event buffer is cleared when the last DBM related
transfer is terminated.
In order to support connect/disconnect and suspend/resume
scenarios, which include starting and stopping of
DBM transfers, it is required to update DBM event
buffer.

Change-Id: If7eca79c779b9fc1fbff6287261c3a3a1476c115
Signed-off-by: Bar Weiner <bweiner@codeaurora.org>