regulator: bd718x7: Constify pointers to 'regulator_desc' wrap struct

Pointer to 'struct regulator_desc' is a pointer to const and the
wrapping structure (container) is not being modified, thus entire syntax
can be replaced to preferred and safer container_of_const().

Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/regulator/bd718x7-regulator.c

···
 			    const struct regulator_desc *desc,
 			    struct regulator_config *cfg)
 {
-	struct bd718xx_regulator_data *data;
+	const struct bd718xx_regulator_data *data;
 
-	data = container_of(desc, struct bd718xx_regulator_data, desc);
+	data = container_of_const(desc, struct bd718xx_regulator_data, desc);
 
 	return rohm_regulator_set_dvs_levels(&data->dvs, np, desc, cfg->regmap);
 }