Add some inventory item interfaces

This commit adds some inventory item interfaces
that represent:

-- Operator Panels
-- Connectors
-- Voltage Regulators
-- Disk backplanes.

Signed-off-by: Santosh Puranik <santosh.puranik@in.ibm.com>
Change-Id: I5b1bd316209946582b42d1096229d6daf25463c1
diff --git a/xyz/openbmc_project/Inventory/Item/DiskBackplane.interface.yaml b/xyz/openbmc_project/Inventory/Item/DiskBackplane.interface.yaml
new file mode 100644
index 0000000..c22de2c
--- /dev/null
+++ b/xyz/openbmc_project/Inventory/Item/DiskBackplane.interface.yaml
@@ -0,0 +1,6 @@
+description: >
+    Implement to provide disk backplane attributes. A disk
+    backplane is a card that typically houses storage disks
+    such as hard drives and SSDs.
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4