net:macb: add line break

Without this patch we see annoying output like this:

---8<---
U-Boot> dhcp
macb1: PHY not foundmacb0: PHY present at 1
macb0: Starting autonegotiation...
--->8---

Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
cc: Joe Hershberger <joe.hershberger@gmail.com>

drivers/net/macb.c

@@ -364,7 +364,7 @@ static int macb_phy_find(struct macb_device *macb)
 	}
 
 	/* PHY isn't up to snuff */
-	printf("%s: PHY not found", macb->netdev.name);
+	printf("%s: PHY not found\n", macb->netdev.name);
 
 	return 0;
 }