Logging.Entry: switch 'AdditionalData' to dict of metadata

All client users of AdditionalData have moved to AdditionalData2,
which is already a dict.  Switch AdditionalData to be a dict as
the next part of the migration.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ic18c8f9eb9804a1221482a96dd682817816d76d9
diff --git a/yaml/xyz/openbmc_project/Logging/Entry.interface.yaml b/yaml/xyz/openbmc_project/Logging/Entry.interface.yaml
index 459809f..1bde9b7 100644
--- a/yaml/xyz/openbmc_project/Logging/Entry.interface.yaml
+++ b/yaml/xyz/openbmc_project/Logging/Entry.interface.yaml
@@ -31,9 +31,9 @@
           with the event. The content of this property is implementation
           defined.
     - name: AdditionalData
-      type: array[string]
+      type: dict[string, string]
       description: >
-          Additional information in the form of metadata field strings VAR=val
+          Additional information in the form of metadata field strings {VAR,val}
     - name: AdditionalData2
       type: dict[string, string]
       description: >