usb: dwc3: gadget: add a trace when disabling EPs

We have a "Enabling %s" trace when enabling an endpoint
but that message felt lonely without a matching
"Disabling %s". Add it.
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/gadget.c

@@ -586,6 +586,8 @@ static int __dwc3_gadget_ep_disable(struct dwc3_ep *dep)
 	struct dwc3		*dwc = dep->dwc;
 	u32			reg;
 
+	dwc3_trace(trace_dwc3_gadget, "Disabling %s", dep->name);
+
 	dwc3_remove_requests(dwc, dep);
 
 	/* make sure HW endpoint isn't stalled */