USB: dwc3: gadget: drop dead hibernation code

USB: dwc3: gadget: drop dead hibernation code

The hibernation code is broken and has never been enabled in mainline
and should thus be dropped.

Remove the hibernation bits from the gadget code, which effectively
reverts commits e1dadd3b0f27 ("usb: dwc3: workaround: bogus hibernation
events") and 7b2a0368bbc9 ("usb: dwc3: gadget: set KEEP_CONNECT in case
of hibernation") except for the spurious interrupt warning.

Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20230404072524.19014-5-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>