Fix member naming for the MultiPressComplete event. (#23895)

It's called PreviousPosition, not NewPosition.

Fixes https://github.com/project-chip/connectedhomeip/issues/23872
diff --git a/examples/chef/devices/rootnode_fan_7N2TobIlOX.matter b/examples/chef/devices/rootnode_fan_7N2TobIlOX.matter
index e750f57..9d6e2b3 100644
--- a/examples/chef/devices/rootnode_fan_7N2TobIlOX.matter
+++ b/examples/chef/devices/rootnode_fan_7N2TobIlOX.matter
@@ -796,7 +796,7 @@
   }
 
   info event MultiPressComplete = 6 {
-    INT8U newPosition = 0;
+    INT8U previousPosition = 0;
     INT8U totalNumberOfPressesCounted = 1;
   }