asoc: wcd938x: Add vdd-buck as on demand supply

On lagoon, vdd-buck need to be dynamic supply.
Add required support to handle buck as dynamic supply.

Change-Id: If6c27fffe0d0c44f178e61a6eae6ef63775c8988
Signed-off-by: Laxminath Kasam <lkasam@codeaurora.org>

include/asoc/msm-cdc-supply.h

@@ -27,6 +27,10 @@ struct cdc_wcd_supply {
 extern int msm_cdc_get_power_supplies(struct device *dev,
 				      struct cdc_regulator **cdc_vreg,
 				      int *total_num_supplies);
+extern bool msm_cdc_is_ondemand_supply(struct device *dev,
+				struct regulator_bulk_data *supplies,
+				struct cdc_regulator *cdc_vreg,
+				int num_supplies, char *supply_name);
 extern int msm_cdc_disable_ondemand_supply(struct device *dev,
 					struct regulator_bulk_data *supplies,
 					struct cdc_regulator *cdc_vreg,