iio: adc: at91-sama5d2_adc: move oversampling storage in its function

Move the storage of oversampling_ratio in at91_adc_config_emr().
This prepares for the next commits.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>

Author: claudiubeznea

drivers/iio/adc/at91-sama5d2_adc.c

@@ -796,6 +796,8 @@ static int at91_adc_config_emr(struct at91_adc_state *st,
 
 	at91_adc_writel(st, EMR, emr);
 
+	st->oversampling_ratio = oversampling_ratio;
+
 	return 0;
 }
 
@@ -1689,7 +1691,6 @@ static int at91_adc_write_raw(struct iio_dev *indio_dev,
 		ret = at91_adc_config_emr(st, val);
 		if (ret)
 			return ret;
-		st->oversampling_ratio = val;
 		return 0;
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		if (val < st->soc_info.min_sample_rate ||