iio: imu: inv_icm42600: switch to use generic name irq get

iio: imu: inv_icm42600: switch to use generic name irq get

Use generic fwnode_irq_get_byname() for getting interrupt pin using
interrupt name. Only INT1 is supported by the driver currently.

If not found fallback to first defined interrupt to keep compatibility.

Signed-off-by: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
Link: https://patch.msgid.link/20250410-iio-imu-inv-icm42600-rework-interrupt-using-names-v4-2-19e4e2f8f7eb@tdk.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>