iio: adis_trigger: Remove code to set trigger parent

iio_trigger_set_drvdata() sets the trigger device parent to first
argument of viio_trigger_alloc(), no need to do it again in the driver
code.
Remove adis_trigger_setup() to match other drivers where setting the
trigger is usually done in the probe() routine.

Signed-off-by: Gwendal Grignou <[e-mail]>
Reviewed-by: Andy Shevchenko <[e-mail]>
Reviewed-by: Nuno Sa <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/imu/adis_trigger.c

···
 	.set_trigger_state = &adis_data_rdy_trigger_set_state,
 };
 
-static void adis_trigger_setup(struct adis *adis)
-{
-	adis->trig->dev.parent = &adis->spi->dev;
-	adis->trig->ops = &adis_trigger_ops;
-	iio_trigger_set_drvdata(adis->trig, adis);
-}
-
 static int adis_validate_irq_flag(struct adis *adis)
 {
 	/*
···
 	if (!adis->trig)
 		return -ENOMEM;
 
-	adis_trigger_setup(adis);
+	adis->trig->ops = &adis_trigger_ops;
+	iio_trigger_set_drvdata(adis->trig, adis);
 
 	ret = adis_validate_irq_flag(adis);
 	if (ret)