dt-bindings: iio: adc: adi,ad7{124,173,192,780}: Allow specifications of a gpio for...

dt-bindings: iio: adc: adi,ad7{124,173,192,780}: Allow specifications of a gpio for irq line

For the AD7124 chip and some of its cousins the logical irq line (R̅D̅Y̅)
is physically on the same pin as the spi MISO output (DOUT) and so
reading a register might trigger an interrupt. For correct operation
it's critical that the actual state of the pin can be read to judge if
an interrupt event is a real one or just a spurious one triggered by
toggling the line in its MISO mode.

Allow specification of an "rdy-gpios" property that references a GPIO
that can be used for that purpose. While this is typically the same GPIO
also used (implicitly) as interrupt source, it is still supposed that
the interrupt is specified as before and usual.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/7fc92a8539e55802d514332e70ee836a3ed08b66.1733504533.git.u.kleine-koenig@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>