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>

include/linux/mfd/da9052/da9052.h

@@ -80,6 +80,7 @@ struct da9052 {
 	struct regmap *regmap;
 
 	int irq_base;
+	struct regmap_irq_chip_data *irq_data;
 	u8 chip_id;
 
 	int chip_irq;