iio: imu: bmi323: Constify struct regmap_bus

`bmi323_regmap_bus` is not modified and can be declared as const to
move its data to a read-only section.
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://patch.msgid.link/20240703-iio-cont-regmap_bus-v1-7-34754f355b65@gmail.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/imu/bmi323/bmi323_i2c.c

@@ -61,7 +61,7 @@ static int bmi323_regmap_i2c_write(void *context, const void *data,
 					      data + sizeof(u8));
 }
 
-static struct regmap_bus bmi323_regmap_bus = {
+static const struct regmap_bus bmi323_regmap_bus = {
 	.read = bmi323_regmap_i2c_read,
 	.write = bmi323_regmap_i2c_write,
 };

drivers/iio/imu/bmi323/bmi323_spi.c

@@ -36,7 +36,7 @@ static int bmi323_regmap_spi_write(void *context, const void *data,
 	return spi_write(spi, data_buff + 1, count - 1);
 }
 
-static struct regmap_bus bmi323_regmap_bus = {
+static const struct regmap_bus bmi323_regmap_bus = {
 	.read = bmi323_regmap_spi_read,
 	.write = bmi323_regmap_spi_write,
 };