Publishing SubModel property on DBUS.

This commit publishes brand as a property on DBUS.
This value will be published for system VPD and will be
picked from this interface to fill the SubModel property
in the ComputerSystem schema of Redfish.

Signed-off-by: Sunny Srivastava <sunnsr25@in.ibm.com>
Change-Id: If0c00f30ffc54715ef8ed796c85c9ffff76489b7
diff --git a/xyz/openbmc_project/Inventory/Decorator/Asset.interface.yaml b/xyz/openbmc_project/Inventory/Decorator/Asset.interface.yaml
index 9e5cecc..d71881e 100644
--- a/xyz/openbmc_project/Inventory/Decorator/Asset.interface.yaml
+++ b/xyz/openbmc_project/Inventory/Decorator/Asset.interface.yaml
@@ -22,3 +22,8 @@
       type: string
       description: >
           The model of the item.
+    - name: SubModel
+      type: string
+      description: >
+          The Sub model of the item.
+      default: ""