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>
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 333a7c0..1f8f730 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -586,6 +586,8 @@
 	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 */