iio: adc: ads1119: Fix IRQ flags

Remove IRQF_TRIGGER_FALLING flag from irq request, this should come from
the platform firmware and should not be hard-coded into the driver.

Add IRQF_ONESHOT flag to the irq request, the interrupt should not be
re-activated in interrupt context, it should be done only after the
device irq handler run.

Fixes: a9306887 ("iio: adc: ti-ads1119: Add driver")
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Reviwed-by: João Paulo Gonçalves <jpaulo.silvagoncalves@gmail.com>
Link: https://patch.msgid.link/20240731140657.88265-1-francesco@dolcini.it


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