usb: gadget: ci13xxx: Cancel pending suspend work before resuming h/w

Composite driver can try to disable pull-up (or disconnect) to carry
out composition switch after bus suspend. There is a possible race in
this scenario between OTG driver trying to suspend hardware and UDC
checking for this state before disabling/enabling pull-up.
Hence, flush OTG driver's suspend work before checking LPM state in UDC.

Change-Id: Id3e6dfda8a41b79678db3388d9d4685a547be9d4
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>