Add 'agent_token' to heartbeat request

Updates the API ref to include the 'agent_token' value in a
heartbeat request (from IPA). New since v1.62
(9341ca4ef7/ironic/api/controllers/v1/versions.py (L102)).

Change-Id: I5eea9704c1bf62561a5505227735159dad7a8e49

api-ref/source/baremetal-api-v1-misc.inc

@@ -97,6 +97,9 @@ Error response codes: 400 404
 .. versionadded:: 1.36 ``agent_version`` parameter for passing the version of
   the Ironic Python Agent to Ironic during heartbeat
 
+.. versionadded:: 1.62 ``agent_token`` parameter for passing the token of
+  the Ironic Python Agent to Ironic during heartbeat
+
 Request
 -------
 
@@ -105,3 +108,4 @@ Request
     - node_ident: node_ident
     - callback_url: callback_url
     - agent_version: agent_version
+    - agent_token: agent_token

api-ref/source/parameters.yaml

@@ -129,6 +129,13 @@ volume_target_id:
   required: true
   type: string
 
+agent_token:
+  description: |
+    The token of the ironic-python-agent ramdisk, sent to the Bare Metal
+    service for authentication purposes.
+  in: query
+  required: true
+  type: string
 agent_version:
   description: |
     The version of the ironic-python-agent ramdisk, sent back to the Bare Metal