vrend: move new added field to the end.

This field was introduced 2 months ago and it breaks virgl
compatibility between guest/host. Switch the new added field
to the end. We will still have compatibility issue but the
"bug window" is much smaller.

Fixes: 7e7a4e7 ("vrend: Introudce VIRGL_CAP_V2_VIDEO_MEMORY to query video memory")

Signed-off-by: Lepton Wu <lepton@chromium.org>
Reviewed-by: Gert Wollny <gert.wollny@collabora.com>

src/virgl_hw.h

@@ -592,8 +592,8 @@ struct virgl_caps_v2 {
         uint32_t host_feature_check_version;
         struct virgl_supported_format_mask supported_readback_formats;
         struct virgl_supported_format_mask scanout;
-        uint32_t max_video_memory;
         uint32_t capability_bits_v2;
+        uint32_t max_video_memory;
 };
 
 union virgl_caps {