Inventory.Decorator.I2CDevice: Add I2CDevice Interface YAML

Define a I2CDevice inventory item interface. This can be implemented by
inventory objects that want to expose i2c device bus number and address
on D-Bus.

One example of how this interface is used can be found in the Entity
Manager repo.

Signed-off-by: Santosh Puranik <santosh.puranik@in.ibm.com>
Change-Id: I236ea86a05f43e46605e4a6f9922156b1d15309f
diff --git a/xyz/openbmc_project/Inventory/Decorator/I2CDevice.interface.yaml b/xyz/openbmc_project/Inventory/Decorator/I2CDevice.interface.yaml
new file mode 100644
index 0000000..c6240ff
--- /dev/null
+++ b/xyz/openbmc_project/Inventory/Decorator/I2CDevice.interface.yaml
@@ -0,0 +1,15 @@
+description: >
+    Implement this interface to expose an I2C device as an inventory item.
+    Properties include the I2C bus number and the device address.
+
+properties:
+    - name: Bus
+      type: size
+      description: >
+          The I2C adapter number as defined in the Linux kernel's i2c dev
+          interface document.
+
+    - name: Address
+      type: size
+      description: >
+          I2C address of the device as defined in the Linux kernel documents.