iio: adc: mp2629_adc: make mp2629_channels const

Add const qualifier to struct iio_chan_spec mp2629_channels[]. This
is read-only data so it can be made const.

Signed-off-by: David Lechner <dlechner@baylibre.com>
Link: https://patch.msgid.link/20250628-iio-const-data-8-v1-1-32ce79494d4a@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Author: dlech

drivers/iio/adc/mp2629_adc.c

@@ -44,7 +44,7 @@ struct mp2629_adc {
 	struct device *dev;
 };
 
-static struct iio_chan_spec mp2629_channels[] = {
+static const struct iio_chan_spec mp2629_channels[] = {
 	MP2629_ADC_CHAN(BATT_VOLT, IIO_VOLTAGE),
 	MP2629_ADC_CHAN(SYSTEM_VOLT, IIO_VOLTAGE),
 	MP2629_ADC_CHAN(INPUT_VOLT, IIO_VOLTAGE),