mfd: wcd934x: Constify struct regmap_config

`wcd934x_regmap_config` 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://lore.kernel.org/r/20240704-mfd-const-regmap_config-v2-4-0c8785b1331d@gmail.comSigned-off-by: Lee Jones <lee@kernel.org>

drivers/mfd/wcd934x.c

@@ -109,7 +109,7 @@ static const struct regmap_range_cfg wcd934x_ranges[] = {
 	},
 };
 
-static struct regmap_config wcd934x_regmap_config = {
+static const struct regmap_config wcd934x_regmap_config = {
 	.reg_bits = 16,
 	.val_bits = 8,
 	.cache_type = REGCACHE_MAPLE,