usb: gadget: f_mbim: Issue wakeup if notification already queued

Selective suspend of device (with remote-wakeup enabled) by host
could race with device driver queuing a notification request on
interrupt endpoint. Driver currently issues remote wakeup if at
the time of queueing notification request device was suspended.
If host suspends device right after driver queues notification
request then device driver fails to initiate remote-wakeup.
Fix this by initiating remote wakeup if there were any pending
notification at the time of suspend.

Change-Id: I0402ad44941b87987381fa27009bdffd519b7e01
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>