power: max17042: 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 <[e-mail]>
Signed-off-by: Sebastian Reichel <[e-mail]>

drivers/power/max17042_battery.c

···
 }
 #endif
 
-static struct regmap_config max17042_regmap_config = {
+static const struct regmap_config max17042_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 16,
 	.val_format_endian = REGMAP_ENDIAN_NATIVE,