net: mdio-gpio: Add support for active low gpio pins

Some systems using mdio-gpio may use active-low gpio pins
(eg with inverters or FETs connected to all or some of the
gpio pins).

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/mdio-gpio.h b/include/linux/mdio-gpio.h
index 7c9fe3c..57e57fe6 100644
--- a/include/linux/mdio-gpio.h
+++ b/include/linux/mdio-gpio.h
@@ -18,6 +18,9 @@
 	unsigned int mdc;
 	unsigned int mdio;
 
+	bool mdc_active_low;
+	bool mdio_active_low;
+
 	unsigned int phy_mask;
 	int irqs[PHY_MAX_ADDR];
 	/* reset callback */