iio: light: make a couple of config structures static

Structures st_uvis25_i2c_regmap_config and st_uvis25_spi_regmap_config are
local to the source and do not need to be in global scope, so make them
both static.

Cleans up sparse warnings:
warning: symbol 'st_uvis25_i2c_regmap_config' was not declared. Should
it be static?
warning: symbol 'st_uvis25_spi_regmap_config' was not declared. Should
it be static?
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/iio/light/st_uvis25_i2c.c

@@ -19,7 +19,7 @@
 
 #define UVIS25_I2C_AUTO_INCREMENT	BIT(7)
 
-const struct regmap_config st_uvis25_i2c_regmap_config = {
+static const struct regmap_config st_uvis25_i2c_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
 	.write_flag_mask = UVIS25_I2C_AUTO_INCREMENT,

drivers/iio/light/st_uvis25_spi.c

@@ -19,7 +19,7 @@
 #define UVIS25_SENSORS_SPI_READ		BIT(7)
 #define UVIS25_SPI_AUTO_INCREMENT	BIT(6)
 
-const struct regmap_config st_uvis25_spi_regmap_config = {
+static const struct regmap_config st_uvis25_spi_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
 	.read_flag_mask = UVIS25_SENSORS_SPI_READ | UVIS25_SPI_AUTO_INCREMENT,