usb: dwc2: host: fix dwc2 disconnect bug

When dwc2 controller detects a disconnect interrupt,
dwc2_hcd_disconnect() should be called immediately to do clean-up
jobs and set port_connect_status_change flag to notify usb hub
driver disconnect status.

Tested-by: Vincent Palatin <vpalatin@chromium.org>
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Yunzhi Li <lyz@rock-chips.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>