mfd: da9052: Fix genirq abuse

Rather than using the pointer passed back by the regmap API (or complaining
because that wasn't actually being set) the da9052 driver was having some
fun and games peering through genirq and regmap internals. Fix the driver
to use the API as expected.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/mfd/da9052-core.c b/drivers/mfd/da9052-core.c
index 7ff313f..7776aff 100644
--- a/drivers/mfd/da9052-core.c
+++ b/drivers/mfd/da9052-core.c
@@ -659,12 +659,11 @@
 	ret = regmap_add_irq_chip(da9052->regmap, da9052->chip_irq,
 				  IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 				  da9052->irq_base, &da9052_regmap_irq_chip,
-				  NULL);
+				  &da9052->irq_data);
 	if (ret < 0)
 		goto regmap_err;
 
-	desc = irq_to_desc(da9052->chip_irq);
-	da9052->irq_base = regmap_irq_chip_get_base(desc->action->dev_id);
+	da9052->irq_base = regmap_irq_chip_get_base(da9052->irq_data);
 
 	ret = mfd_add_devices(da9052->dev, -1, da9052_subdev_info,
 			      ARRAY_SIZE(da9052_subdev_info), NULL, 0);
@@ -681,8 +680,7 @@
 
 void da9052_device_exit(struct da9052 *da9052)
 {
-	regmap_del_irq_chip(da9052->chip_irq,
-			    irq_get_irq_data(da9052->irq_base)->chip_data);
+	regmap_del_irq_chip(da9052->chip_irq, da9052->irq_data);
 	mfd_remove_devices(da9052->dev);
 }