To avoid excessive mdio bus transactions during probing, mask all phy
addresses that do not exist (there is a 1:1 mapping between switch port
number and phy address).
Suggested-by: Andrew Lunn <andrew@xxxxxxx>
Signed-off-by: Klaus Kudielka <klaus.kudielka@xxxxxxxxx>
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>