iio: magn: ak8974: use irq_get_trigger_type()

Use irq_get_trigger_type() to replace getting the irq data then the
type in two steps.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patch.msgid.link/20240901135950.797396-15-jic23@kernel.org


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>