schemas: chassis types for Inventory.Item.Chassis

This commit add the chassis types and corresponding interface as
described in [1].

[1] https://github.com/openbmc/phosphor-dbus-interfaces/blob/master/yaml/xyz/openbmc_project/Inventory/Item/Chassis.interface.yaml

Tested:
Interfaces are added with the corresponding properties RackMount
and Blade under the related path.

Change-Id: Id0cb2b2450b290d0d2af994d07cec301b441ab2d
Signed-off-by: Sean He <sean.he.wiwynn@gmail.com>
diff --git a/schemas/openbmc-dbus.json b/schemas/openbmc-dbus.json
index 24f71b9..528d2b2 100644
--- a/schemas/openbmc-dbus.json
+++ b/schemas/openbmc-dbus.json
@@ -118,6 +118,11 @@
                         },
                         "Chassis": {
                             "additionalProperties": false,
+                            "properties": {
+                                "ChassisType": {
+                                    "type": "string"
+                                }
+                            },
                             "type": "object"
                         },
                         "NetworkInterface": {