usb: gadget: Remove unnecessary notification in MBIM after bus resume

In case of a bus suspend when there are pending packets on notify EP
an unnecessary additional notification would be added, which results
in EP stall.
This fix handles this scenario and also remove unused code on MBIM
function.

Change-Id: Ief6733b6659a9ac628f7311debb0f6eef2e70a5d
CRs-Fixed: 470665
Signed-off-by: Bar Weiner <bweiner@codeaurora.org>