iio: jsa1212: Constify struct regmap_config

The regmap_config struct may be const because it is not modified by the
driver and regmap_init() accepts pointer to const.
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/light/jsa1212.c

@@ -308,7 +308,7 @@ static bool jsa1212_is_volatile_reg(struct device *dev, unsigned int reg)
 	}
 }
 
-static struct regmap_config jsa1212_regmap_config = {
+static const struct regmap_config jsa1212_regmap_config = {
 	.name =  JSA1212_REGMAP_NAME,
 	.reg_bits = 8,
 	.val_bits = 8,