usb: dwc3: msm: initiate resume sequence in threaded irq handler

Since going out of low power mode(LPM) requires enabling
USB clocks, it cannot be done in interrupt context.

This change moves LPM-exit sequence to the threaded
irq handler and is now done synchronously, this is
done to ensure that enabling the clocks happens as
soon as possible.

Change-Id: I908df91e2cb5a1ae64c748a8006b5dad2c1d026f
Signed-off-by: Bar Weiner <bweiner@codeaurora.org>