mfd: arizona: Fix typo in arizona_irq_map

The type of the data for the main Arizona IRQ chip should be struct
arizona not struct regmap_irq_chip_data. The bug is harmless but should
probably be corrected anyway.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>