d3d12: Use DirectX-Headers wrap for d3d12.h

This does 2 things for us:
1. Allows us to compile-time depend on any features from new headers,
   instead of having to conditionally compile based on Windows SDK version.
2. Allows us to reference d3d12.h when compiling for non-Windows.

Reviewed-by: Bill Kristiansen <billkris@microsoft.com>
Reviewed-by: Dylan Baker <dylan@pnwbakers.com>
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7937>

src/microsoft/resource_state_manager/D3D12ResourceState.h

@@ -26,7 +26,7 @@
 
 #include <vector>
 #include <assert.h>
-#include <d3d12.h>
+#include <directx/d3d12.h>
 
 #include "util/list.h"
 

src/microsoft/resource_state_manager/meson.build

@@ -28,7 +28,7 @@ libd3d12_resource_state = static_library(
   files_libd3d12_resource_state,
   gnu_symbol_visibility : 'hidden',
   include_directories : [inc_include, inc_src, inc_mesa],
-  dependencies: [],
+  dependencies: [dep_dxheaders],
 )
 
 idep_libd3d12_resource_state = declare_dependency(