pdmgen: Require uppercase meta keys

journald ignores lowercase metadata keys so require them
to be uppercase.  Abort the config file parse when lowercase
keys are found.

Change-Id: Icffffdc6680b4d305329c3395f8e2fda6210964f
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/src/example/example.yaml b/src/example/example.yaml
index 899c4c8..6a1685f 100644
--- a/src/example/example.yaml
+++ b/src/example/example.yaml
@@ -18,13 +18,13 @@
   class: group
   group: path
   members:
-    - meta: path
+    - meta: PATH
       path: /xyz/openbmc_project/testing/inst1
-    - meta: path
+    - meta: PATH
       path: /xyz/openbmc_project/testing/inst2
-    - meta: path
+    - meta: PATH
       path: /xyz/openbmc_project/testing/inst3
-    - meta: path
+    - meta: PATH
       path: /xyz/openbmc_project/testing/inst4
 
 - name: example property group
@@ -39,10 +39,10 @@
   type: uint32
   members:
     - interface: xyz.openbmc_project.Sensor.Value
-      meta: property
+      meta: PROPERTY
       property: ValueA
     - interface: xyz.openbmc_project.Sensor.Value
-      meta: property
+      meta: PROPERTY
       property: ValueB
 
 - name: example property watch