All existing TI SoCs network HW have similar MDIO implementation, so
introduce common mdio support library which can be reused by TI networking
drivers.
Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
