dwc2: use the nonblock argument in submit_int_msg

An USB 1.1 keyboard connected to dwc2 through a high-speed hub does not
report status until it changes. With this patch you can enable keyboard
by pressing a key while USB devices are probed. Without a keypress no
state is reported and the probe times out. We don't want to wait for a
keypress or timeout while polling for keypresses so implement an int_msg
nonblock variant that exits early on error.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
diff --git a/drivers/usb/host/dwc2.c b/drivers/usb/host/dwc2.c
index bc61662..350d820 100644
--- a/drivers/usb/host/dwc2.c
+++ b/drivers/usb/host/dwc2.c
@@ -1123,7 +1123,7 @@
 			return -ETIMEDOUT;
 		}
 		ret = _submit_bulk_msg(priv, dev, pipe, buffer, len);
-		if (ret != -EAGAIN)
+		if ((ret != -EAGAIN) || nonblock)
 			return ret;
 	}
 }