Redfish event subscription failing on iLO6 hardware due to usage of older schema

Event subscription of Ironic Redfish driver is failing on iLO6 based HPE hardware, since Ironic redfish driver using deprecated attribute (EventTypes) in redfish schema, and iLO6 is expecting the latest one (RegistryPrefixes).

Payload of Ironic redfish driver for "create_subscription":

payload = {
            'Destination'
            'Protocol'
            'Context'
            'EventTypes'
}

Payload iLO6 expecting for "create_subscription":
payload = {
            'Destination'
            'Protocol'
            'Context'
            'RegistryPrefixes'
}