i2c-vr: add RAA22X Gen2 support

Extend ISL69269 to support Renesas Gen2 VR devices which share
similar programming interfaces but use slightly different registers.

Tested:
```
1. Check firmware info: (current version 5FFB1D09)
~$ curl -k -u root:0penBmc -X GET https://10.2.230.66/redfish/v1/UpdateService/FirmwareInventory/Catalina_PDB_vr_n1_8217
{
  "@odata.id": "/redfish/v1/UpdateService/FirmwareInventory/Catalina_PDB_vr_n1_8217",
  "@odata.type": "#SoftwareInventory.v1_1_0.SoftwareInventory",
  "Description": "Unknown image",
  "Id": "Catalina_PDB_vr_n1_8217",
  "Name": "Software Inventory",
  "Status": {
    "Health": "OK",
    "HealthRollup": "OK",
    "State": "Enabled"
  },
  "Updateable": true,
  "Version": "5FFB1D09"
}

2. Trigger Update: (update to version C001A89C)
~$ curl -k -u root:0penBmc \
-H "Content-Type:multipart/form-data" \
-X POST \
-F UpdateParameters="{\"Targets\":[\"/redfish/v1/UpdateService/FirmwareInventory/Catalina_PDB_vr_n1_8217\"],\"@Redfish.OperationApplyTime\":\"OnReset\"};type=application/json" \
-F "UpdateFile=@catalina-raa-n1_C001A89C.pldm;type=application/octet-stream" \
https://10.2.230.66/redfish/v1/UpdateService/update-multipart
{
  "@odata.id": "/redfish/v1/TaskService/Tasks/0",
  "@odata.type": "#Task.v1_4_3.Task",
  "HidePayload": false,
  "Id": "0",
  "Messages": [
    {
      "@odata.type": "#Message.v1_1_1.Message",
      "Message": "The task with Id '0' has started.",
      "MessageArgs": [
        "0"
      ],
      "MessageId": "TaskEvent.1.0.TaskStarted",
      "MessageSeverity": "OK",
      "Resolution": "None."
    }
  ],
  "Name": "Task 0",
  "Payload": {
    "HttpHeaders": [],
    "HttpOperation": "POST",
    "TargetUri": "/redfish/v1/UpdateService/update-multipart"
  },
  "PercentComplete": 0,
  "StartTime": "2025-09-17T17:15:50+00:00",
  "TaskMonitor": "/redfish/v1/TaskService/TaskMonitors/0",
  "TaskState": "Running",
  "TaskStatus": "OK"
}

3. After AC cycle check firmware info again:
~$ curl -k -u root:0penBmc -X GET https://10.2.230.66/redfish/v1/UpdateService/FirmwareInventory/Catalina_PDB_vr_n1_332
{
  "@odata.id": "/redfish/v1/UpdateService/FirmwareInventory/Catalina_PDB_vr_n1_332",
  "@odata.type": "#SoftwareInventory.v1_1_0.SoftwareInventory",
  "Description": "Unknown image",
  "Id": "Catalina_PDB_vr_n1_332",
  "Name": "Software Inventory",
  "Status": {
    "Health": "OK",
    "HealthRollup": "OK",
    "State": "Enabled"
  },
  "Updateable": true,
  "Version": "C001A89C"
}
```

Change-Id: Idd8e3d147a0191b45f465508e13b4ac0bc94e92a
Signed-off-by: Cosmo Chou <cosmo.chou@quantatw.com>
diff --git a/i2c-vr/isl69269/isl69269.hpp b/i2c-vr/isl69269/isl69269.hpp
index 789bc34..8d9ea01 100644
--- a/i2c-vr/isl69269/isl69269.hpp
+++ b/i2c-vr/isl69269/isl69269.hpp
@@ -13,7 +13,14 @@
 class ISL69269 : public VoltageRegulator
 {
   public:
-    ISL69269(sdbusplus::async::context& ctx, uint16_t bus, uint16_t address);
+    enum class Gen
+    {
+        Gen2,
+        Gen3
+    };
+
+    ISL69269(sdbusplus::async::context& ctx, uint16_t bus, uint16_t address,
+             Gen gen = Gen::Gen3);
 
     sdbusplus::async::task<bool> verifyImage(const uint8_t* image,
                                              size_t imageSize) final;
@@ -57,6 +64,7 @@
     bool checkImage();
 
     phosphor::i2c::I2C i2cInterface;
+    Gen generation;
     uint8_t mode;
 
     struct Configuration configuration;