Fallback to junction temperature and socket power

If the card does not have edge temperature, fallback to junction
temperature. If the card only have socket power, then use socket
power instead.

Change-Id: I053a67a89cf3b29a34e82123f522c08d7dd68916

python_binding/rdc_collectd.py

@@ -65,7 +65,7 @@ def config_func(config):
         if key == 'field_ids':
             field_ids = []
             for f in node.values:
-                field_id = rdc.get_field_id_from_name(f)
+                field_id = rdc.get_field_id_from_name(str.encode(f))
                 if field_id.value == rdc_field_t.RDC_FI_INVALID:
                     print("Invalid field '%s' will be ignored." % (f))
                 else: