usb: chipidea: imx: Warn if oc polarity isn't specified

The polarity of the over current detection pin isn't configured on i.MX6/7
if it's unspecified in the device tree. So the actual configuration depends
on bootloader behavior which is bad.

So encourage users to fix their device tree by issuing a warning in this
case.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Peter Chen <peter.chen@nxp.com>

drivers/usb/chipidea/ci_hdrc_imx.c

@@ -148,6 +148,8 @@ static struct imx_usbmisc_data *usbmisc_get_init_data(struct device *dev)
 	} else if (of_find_property(np, "over-current-active-low", NULL)) {
 		data->oc_pol_active_low = 1;
 		data->oc_pol_configured = 1;
+	} else {
+		dev_warn(dev, "No over current polarity defined\n");
 	}
 
 	if (of_find_property(np, "external-vbus-divider", NULL))