iio: light: as73211: Increase measurement timeout

We found some sensors which are much slower (20% at room temperature)
than nominal. According to the data sheet, up to 27% is possible. Now I
add 33% to the nominal time out, hopefully this is enough.
Signed-off-by: Christian Eggers <ceggers@arri.de>
Link: https://lore.kernel.org/r/20200909154439.10308-1-ceggers@arri.de
Fixes: 403e5586 ("iio: light: as73211: New driver")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/light/as73211.c

@@ -259,10 +259,9 @@ static int as73211_req_data(struct as73211_data *data)
 	data->osr &= ~AS73211_OSR_SS;
 
 	/*
-	 * Add some extra margin for the timeout. sensor timing is not as precise
-	 * as our one ...
+	 * Add 33% extra margin for the timeout. fclk,min = fclk,typ - 27%.
 	 */
-	time_us += time_us / 8;
+	time_us += time_us / 3;
 	if (data->client->irq) {
 		ret = wait_for_completion_timeout(&data->completion, usecs_to_jiffies(time_us));
 		if (!ret) {