mfd: fsl-imx25-tsadc: Constify struct regmap_config

`mx25_tsadc_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-v2-2-0c8785b1331d@gmail.comSigned-off-by: Lee Jones <lee@kernel.org>

drivers/mfd/fsl-imx25-tsadc.c

@@ -16,7 +16,7 @@
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 
-static struct regmap_config mx25_tsadc_regmap_config = {
+static const struct regmap_config mx25_tsadc_regmap_config = {
 	.fast_io = true,
 	.max_register = 8,
 	.reg_bits = 32,