net: dsa: mv88e6xxx: Use the DT IRQ trigger mode

By calling request_threaded_irq() with the flag IRQF_TRIGGER_FALLING
we override the trigger mode provided in device tree. And the
interrupt is actually active low, which is what all the current device
tree descriptions use.
Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/chip.c

@@ -425,7 +425,7 @@ static int mv88e6xxx_g1_irq_setup(struct mv88e6xxx_chip *chip)
 
 	err = request_threaded_irq(chip->irq, NULL,
 				   mv88e6xxx_g1_irq_thread_fn,
-				   IRQF_ONESHOT | IRQF_TRIGGER_FALLING,
+				   IRQF_ONESHOT,
 				   dev_name(chip->dev), chip);
 	if (err)
 		mv88e6xxx_g1_irq_free_common(chip);