Throttle, Item: Add throttling association

Create association documentation between Throttle and Item.

Signed-off-by: George Liu <liuxiwei@ieisystem.com>
Change-Id: Iae6b1d370077f91e2e6d25ef82f2dfcf8bf0051b
diff --git a/yaml/xyz/openbmc_project/Control/Power/Throttle.interface.yaml b/yaml/xyz/openbmc_project/Control/Power/Throttle.interface.yaml
index 04c4a13..5a33494 100644
--- a/yaml/xyz/openbmc_project/Control/Power/Throttle.interface.yaml
+++ b/yaml/xyz/openbmc_project/Control/Power/Throttle.interface.yaml
@@ -40,3 +40,12 @@
           - name: Unknown
             description: >
                 The cause of the component being throttled is not known.
+
+associations:
+    - name: throttling
+      description: >
+          Objects implementing Throttle can optionally implement the
+          'throttling' association to provide a link to an Item.
+      reverse_name: throttled_by
+      required_endpoint_interfaces:
+          - xyz.openbmc_project.Inventory.Item
diff --git a/yaml/xyz/openbmc_project/Inventory/Item.interface.yaml b/yaml/xyz/openbmc_project/Inventory/Item.interface.yaml
index 3bb9683..4eec2bb 100644
--- a/yaml/xyz/openbmc_project/Inventory/Item.interface.yaml
+++ b/yaml/xyz/openbmc_project/Inventory/Item.interface.yaml
@@ -79,6 +79,13 @@
       reverse_name: powering
       required_endpoint_interfaces:
           - xyz.openbmc_project.Inventory.Item.PowerSupply
+    - name: throttled_by
+      description: >
+          Objects that implement Chassis can optionally implement the
+          'throttled_by' association to provide a link to throttle.
+      reverse_name: throttling
+      required_endpoint_interfaces:
+          - xyz.openbmc_project.Control.Power.Throttle
     - name: sensors
       description: >
           Sensors may implement an 'inventory' to 'sensors' association with the
diff --git a/yaml/xyz/openbmc_project/Inventory/Item/README.md b/yaml/xyz/openbmc_project/Inventory/Item/README.md
index dda2ad2..6712abc 100644
--- a/yaml/xyz/openbmc_project/Inventory/Item/README.md
+++ b/yaml/xyz/openbmc_project/Inventory/Item/README.md
@@ -26,3 +26,4 @@
 - PowerSupply and Item: `{powering, powered_by}`
 - FabricAdapter and Connector.Port: `{connecting, connected_to}`
 - Cpu and PCIeSlot: `{connecting, connected_to}`
+- Control.Throttle and Item: `{throttling, throttled_by}`