Logging: Create the new event interface.

This interface should be instantiated for the phosphor::events
namespace.

Currently Event interface and Entry Interface has common
properties but the plan is to split the Entry interface into
Event and Entry specific properties.

Will do it later with github issue
https://github.com/openbmc/openbmc/issues/2923

Change-Id: Ic84ea85d20126473e2723e4868c685f0a9d298e0
Signed-off-by: Ratan Gupta <ratagupt@in.ibm.com>
diff --git a/xyz/openbmc_project/Logging/Event.interface.yaml b/xyz/openbmc_project/Logging/Event.interface.yaml
new file mode 100755
index 0000000..c083fc9
--- /dev/null
+++ b/xyz/openbmc_project/Logging/Event.interface.yaml
@@ -0,0 +1,32 @@
+#TODO This interface and the logging entry interface
+#     is having common properties,Ideally there should be
+#     one common interface and the specific properties
+#     for logging should go in (Logging/Entry).
+#     https://github.com/openbmc/openbmc/issues/2923
+description: >
+    Implement to provide event entry attributes.
+    This interface should be instantiated for the phosphor::events namespace.
+    This interface is a collection of objects, therefore it is required to
+    implement org.freedesktop.DBus.ObjectManager on the events namespace root.
+    Optionally, implement xyz.openbmc_project.Delete to allow the deletion of
+    individual entries.
+    The event D-Bus object path would look like
+    <PhosphorDbusRoot>/events/<type>/<id>
+    Here "type" is the type of event, Could be network/system state event etc.
+    Type would be given by the application configuration file which would
+    be implementing this interface.
+    Here "id" is positive integer starts from 1 and it gets incremented by 1
+    with any newly created object.
+properties:
+    - name: Timestamp
+      type: uint64
+      description: >
+          Event creation timestamp in milliseconds since 1970.
+    - name: Message
+      type: string
+      description: >
+          The message description of the event entry.
+    - name: AdditionalData
+      type: array[string]
+      description: >
+          Additional information in the form of metadata field strings VAR=val