iio: adc: ad7606: fix standby gpio state to match the documentation

The binding's documentation specifies that "As the line is active low, it
should be marked GPIO_ACTIVE_LOW". However, in the driver, it was handled
the opposite way. This commit sets the driver's behaviour in sync with the
documentation

Fixes: 722407a4 ("staging:iio:ad7606: Use GPIO descriptor API")
Signed-off-by: Guillaume Stols <gstols@baylibre.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/ad7606.c

@@ -443,7 +443,7 @@ static int ad7606_request_gpios(struct ad7606_state *st)
 		return PTR_ERR(st->gpio_range);
 
 	st->gpio_standby = devm_gpiod_get_optional(dev, "standby",
-						   GPIOD_OUT_HIGH);
+						   GPIOD_OUT_LOW);
 	if (IS_ERR(st->gpio_standby))
 		return PTR_ERR(st->gpio_standby);
 
@@ -686,7 +686,7 @@ static int ad7606_suspend(struct device *dev)
 
 	if (st->gpio_standby) {
 		gpiod_set_value(st->gpio_range, 1);
-		gpiod_set_value(st->gpio_standby, 0);
+		gpiod_set_value(st->gpio_standby, 1);
 	}
 
 	return 0;