headers: explicitly define Reserved bits in DXVAHD_BLT_STATE structures

As defined in the documentation https://learn.microsoft.com/en-us/windows/win32/api/dxvahd/ns-dxvahd-dxvahd_blt_state_output_color_space_data

and https://learn.microsoft.com/en-us/windows/win32/api/dxvahd/ns-dxvahd-dxvahd_stream_state_input_color_space_data

Signed-off-by: LIU Hao <lh_mouse@126.com>
diff --git a/mingw-w64-headers/include/dxvahd.idl b/mingw-w64-headers/include/dxvahd.idl
index bf00ca6..3bb5e50 100644
--- a/mingw-w64-headers/include/dxvahd.idl
+++ b/mingw-w64-headers/include/dxvahd.idl
@@ -212,10 +212,16 @@
 } DXVAHD_BLT_STATE_CONSTRICTION_DATA;
 
 typedef struct _DXVAHD_BLT_STATE_OUTPUT_COLOR_SPACE_DATA {
-  UINT Usage  :1;
-  UINT RGB_Range  :1;
-  UINT YCbCr_Matrix  :1;
-  UINT YCbCr_xvYCC  :1;
+  union {
+    struct {
+      UINT Usage  :1;
+      UINT RGB_Range  :1;
+      UINT YCbCr_Matrix  :1;
+      UINT YCbCr_xvYCC  :1;
+      UINT Reserved : 28;
+    };
+    UINT Value;
+  };
 } DXVAHD_BLT_STATE_OUTPUT_COLOR_SPACE_DATA;
 
 typedef struct _DXVAHD_BLT_STATE_PRIVATE_DATA {
@@ -308,10 +314,15 @@
 } DXVAHD_STREAM_STATE_FRAME_FORMAT_DATA;
 
 typedef struct _DXVAHD_STREAM_STATE_INPUT_COLOR_SPACE_DATA {
-  UINT Type  :1;
-  UINT RGB_Range  :1;
-  UINT YCbCr_Matrix  :1;
-  UINT YCbCr_xvYCC  :1;
+  union {
+    struct {
+      UINT Type  :1;
+      UINT RGB_Range  :1;
+      UINT YCbCr_Matrix  :1;
+      UINT YCbCr_xvYCC  :1;
+    };
+    UINT Value;
+  };
 } DXVAHD_STREAM_STATE_INPUT_COLOR_SPACE_DATA;
 
 typedef struct _DXVAHD_STREAM_STATE_LUMA_KEY_DATA {