Logging: add event for clearing

The phosphor-logging had an internal event reported for when the event
log is cleared.  Create an equivalent event here for better
documentation (and using the new event format).

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ia8e0e329c5a2818376f0fb313531a1040af23dd6
diff --git a/yaml/xyz/openbmc_project/Logging.events.yaml b/yaml/xyz/openbmc_project/Logging.events.yaml
new file mode 100644
index 0000000..e582c38
--- /dev/null
+++ b/yaml/xyz/openbmc_project/Logging.events.yaml
@@ -0,0 +1,11 @@
+version: 1.0.0
+
+events:
+    - name: Cleared
+      en:
+          description: Indicate the user cleared all logs.
+          message: Event log cleared by user.
+      metadata:
+          - name: NUMBER_OF_LOGS
+            description: The number of logs present before clearing.
+            type: uint64