misc: Update to Vulkan header version 20

Changes:
vulkan.h
json files
linux SO version
loader and tests to reflect API change in vkCmdUpdateBuffer
vk.xml to match Vulkan-Docs

Change-Id: I1763bca6fccf619ad8e76c0363f68fa38ad69900
diff --git a/vulkan.py b/vulkan.py
index 56c18b6..ea78e64 100644
--- a/vulkan.py
+++ b/vulkan.py
@@ -883,7 +883,7 @@
              Param("VkBuffer", "dstBuffer"),
              Param("VkDeviceSize", "dstOffset"),
              Param("VkDeviceSize", "dataSize"),
-             Param("const uint32_t*", "pData")]),
+             Param("const void*", "pData")]),
 
         Proto("void", "CmdFillBuffer",
             [Param("VkCommandBuffer", "commandBuffer"),