change(ldo): make ldo driver unit_id same as datasheet

Prior to this commit, we expect passing ldo_unit_t to esp_ldo driver
`ldo_unit` field. And ldo_unit_t will alias the LDO unit to values
starting from 0, e.g. LDO_UNIT_1 is actually value 0.

With this commit, esp_ldo driver `ldo_unit` field will start with 1,
which is aligned with the datasheet. So LDO_UNIT_1 is in value 1,
meanwhile setting 1 to `ldo_unit` will work as well.

components/esp_hw_support/include/esp_private/esp_ldo.h

@@ -31,7 +31,7 @@ typedef struct {
  * @brief LDO driver initial configurations
  */
 typedef struct {
-    int unit_id;               ///< LDO unit
+    int unit_id;                    ///< LDO ID, this is aligned with datasheet, e.g. you should set this to 1, if using LDO ID 1
     esp_ldo_unit_cfg_t cfg;         ///< LDO unit configuration
     struct {
         uint32_t enable_unit: 1;    ///< Enable the LDO unit after it's initialised