usb: dwc3: gadget: conditionally disable Link State change events

Link State Change events are only needed for
debugging and to apply certain workarounds on known
errata. Let's save a few cycles by disabling these
events completely on working revisions of the core.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/gadget.c

@@ -1537,11 +1537,13 @@ static void dwc3_gadget_enable_irq(struct dwc3 *dwc)
 			DWC3_DEVTEN_CMDCMPLTEN |
 			DWC3_DEVTEN_ERRTICERREN |
 			DWC3_DEVTEN_WKUPEVTEN |
-			DWC3_DEVTEN_ULSTCNGEN |
 			DWC3_DEVTEN_CONNECTDONEEN |
 			DWC3_DEVTEN_USBRSTEN |
 			DWC3_DEVTEN_DISCONNEVTEN);
 
+	if (dwc->revision < DWC3_REVISION_250A)
+		reg |= DWC3_DEVTEN_ULSTCNGEN;
+
 	dwc3_writel(dwc->regs, DWC3_DEVTEN, reg);
 }