usb: dwc3: Fix non-usb3 configurations

Missing nodes may also be signaled via -ENODATA. We need to check for
that to prevent failing in non-usb3 setups.

Furthermore, dev.phy must be NULL'ed in case usb3-phy was not found.

Fixes: 142d50fbce7c ("usb: dwc3: Add support for usb3-phy PHY configuration")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
diff --git a/drivers/usb/dwc3/dwc3-generic.c b/drivers/usb/dwc3/dwc3-generic.c
index 6e1a1d0..c5310e4 100644
--- a/drivers/usb/dwc3/dwc3-generic.c
+++ b/drivers/usb/dwc3/dwc3-generic.c
@@ -468,9 +468,11 @@
 		ret = generic_phy_init(&phy);
 		if (ret)
 			return ret;
-	} else if (ret != -ENOENT) {
+	} else if (ret != -ENOENT && ret != -ENODATA) {
 		debug("could not get phy (err %d)\n", ret);
 		return ret;
+	} else {
+		phy.dev = NULL;
 	}
 
 	glue->regs = dev_read_addr(dev);