usb: dwc3: gadget: Set link state to RX_Detect on disconnect

When DWC3 receives disconnect event, it needs to set the link state to
RX_Detect.

DWC_usb3 3.30a programming guide 4.1.7
Signed-off-by: NThinh Nguyen <thinhn@synopsys.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/dwc3/gadget.c

@@ -2759,6 +2759,8 @@ static void dwc3_gadget_disconnect_interrupt(struct dwc3 *dwc)
 {
 	int			reg;
 
+	dwc3_gadget_set_link_state(dwc, DWC3_LINK_STATE_RX_DET);
+
 	reg = dwc3_readl(dwc->regs, DWC3_DCTL);
 	reg &= ~DWC3_DCTL_INITU1ENA;
 	reg &= ~DWC3_DCTL_INITU2ENA;