Drive: Add Drive Type for Item.Drive Interface

Add support for Drive Types for
- HDD
- SSD

All other drive type will be represented as `Unknown`.

Change-Id: If067553135898a3a47b161f59d3867feddd8a93d
Signed-off-by: Willy Tu <wltu@google.com>
diff --git a/yaml/xyz/openbmc_project/Inventory/Item/Drive.interface.yaml b/yaml/xyz/openbmc_project/Inventory/Item/Drive.interface.yaml
index be17e7c..3460ed0 100644
--- a/yaml/xyz/openbmc_project/Inventory/Item/Drive.interface.yaml
+++ b/yaml/xyz/openbmc_project/Inventory/Item/Drive.interface.yaml
@@ -1,2 +1,26 @@
 description: >
     Implement to provide drive attributes.
+
+properties:
+    - name: Type
+      default: Unknown
+      type: enum[self.DriveType]
+      description: >
+          The type of physical form factor of the Drive.
+
+enumerations:
+    - name: DriveType
+      description: >
+          Possible Drive type
+      values:
+          - name: HDD
+            description: >
+                A hard disk drive is an electro-mechanical data storage device
+                that stores and retrieves digital data using magnetic storage.
+          - name: SSD
+            description: >
+                A solid-state drive is a solid-state storage device that uses
+                integrated circuit assemblies to store data persistently.
+          - name: Unknown
+            description: >
+                The Drive type is unknown.