drm/vmwgfx: remove unused struct 'vmw_stdu_dma'

'vmw_stdu_dma' is unused since
commit 39985eea ("drm/vmwgfx: Abstract placement selection")
Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240517232858.230860-1-linux@treblig.org

drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c

@@ -92,11 +92,6 @@ struct vmw_stdu_update {
 	SVGA3dCmdUpdateGBScreenTarget body;
 };
 
-struct vmw_stdu_dma {
-	SVGA3dCmdHeader     header;
-	SVGA3dCmdSurfaceDMA body;
-};
-
 struct vmw_stdu_surface_copy {
 	SVGA3dCmdHeader      header;
 	SVGA3dCmdSurfaceCopy body;