phy: Centralise print about attached phy

Many Ethernet drivers contain the same netdev_info() print statement
about the attached phy. Move it into the phy device code. Additionally
add a varargs function which can be used to append additional
information.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 1e9e942..5f45e68 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -1080,11 +1080,10 @@
 			netdev_err(slave_dev, "failed to connect to port %d: %d\n", p->port, ret);
 			return ret;
 		}
-	} else {
-		netdev_info(slave_dev, "attached PHY at address %d [%s]\n",
-			    p->phy->addr, p->phy->drv->name);
 	}
 
+	phy_attached_info(p->phy);
+
 	return 0;
 }