Add iDRAC Redfish firmware update test

This adds test for firmware update using iDRAC redfish.

Change-Id: I87bacfabcaf94b9b80b884d6ab576058e7411f84
diff --git a/ironic_tempest_plugin/config.py b/ironic_tempest_plugin/config.py
index c812300..19070b3 100644
--- a/ironic_tempest_plugin/config.py
+++ b/ironic_tempest_plugin/config.py
@@ -168,6 +168,18 @@
                 help="List of Ironic enabled power interfaces."),
     cfg.StrOpt('default_rescue_interface',
                help="Ironic default rescue interface."),
+    cfg.StrOpt('firmware_image_url',
+               help="Image URL of firmware image file supported by "
+                    "update_firmware clean step."),
+    cfg.StrOpt('firmware_image_checksum',
+               help="SHA1 checksum of firmware image file."),
+    cfg.StrOpt('firmware_rollback_image_url',
+               help="Image URL of firmware update cleaning step's "
+                    "rollback image. Optional. If not provided, "
+                    "rollback is skipped."),
+    cfg.StrOpt('firmware_rollback_image_checksum',
+               help="SHA1 checksum of firmware rollback image file. "
+                    "This is required if firmware_rollback_image_url is set."),
     cfg.IntOpt('adjusted_root_disk_size_gb',
                min=0,
                help="Ironic adjusted disk size to use in the standalone tests "