usb: dwc3: gadget: start resume sequence on remote-wakeup

As per Synopsys databook, the USB controller does not
trigger a wakeup event when remote-wakeup is used.
Hence, after remote-wakeup sequence is complete, and
the device is back at U0 state, it is required that
the resume sequence is initiated manually by SW.

Change-Id: I2f147d4a0644088b948b1798627c7717c35c0104
Signed-off-by: Bar Weiner <bweiner@codeaurora.org>
Signed-off-by: Dov Levenglick <dovl@codeaurora.org>