iio: humidity: hts221: use irq_get_trigger_type()

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

Reviewed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20240901135950.797396-8-jic23@kernel.org


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