svga: mark dest image as defined in svga_surface_copy()

After we blit/copy to a dest texture image we need to mark it as
being defined.  This fixes broken mipmap generation for quite a
few texture formats.  Mipgen involves making texture views and
svga_texture_view_surface() skips texture images that are undefined.

Cc: "10.0" <mesa-stable@lists.freedesktop.org>

Reviewed-by: José Fonseca <jfonseca@vmware.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
(cherry picked from commit 3969330b47)

src/gallium/drivers/svga/svga_pipe_blit.c

@@ -148,6 +148,8 @@ static void svga_surface_copy(struct pipe_context *pipe,
 
 #endif
 
+   /* Mark the destination image as being defined */
+   svga_define_texture_level(dtex, dst_face, dst_level);
 }