bug 14868: Replace VkTimestampType with VkPipelineStageFlagBits (WIP)

https://cvs.khronos.org/bugzilla/show_bug.cgi?id=14868
diff --git a/vulkan.py b/vulkan.py
index c48de90..57f0058 100755
--- a/vulkan.py
+++ b/vulkan.py
@@ -945,7 +945,7 @@
 
         Proto("void", "CmdWriteTimestamp",
             [Param("VkCmdBuffer", "cmdBuffer"),
-             Param("VkTimestampType", "timestampType"),
+             Param("VkPipelineStageFlagBits", "pipelineStage"),
              Param("VkBuffer", "destBuffer"),
              Param("VkDeviceSize", "destOffset")]),