console: rework DisplaySurface handling [dcl/ui side]

Replace the dpy_gfx_resize and dpy_gfx_setdata DisplayChangeListener
callbacks with a dpy_gfx_switch callback which notifies the ui code
when the framebuffer backing storage changes.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
diff --git a/include/ui/console.h b/include/ui/console.h
index 63e6e66..c8f0050 100644
--- a/include/ui/console.h
+++ b/include/ui/console.h
@@ -156,10 +156,9 @@
     void (*dpy_gfx_update)(DisplayChangeListener *dcl,
                            struct DisplayState *s,
                            int x, int y, int w, int h);
-    void (*dpy_gfx_resize)(DisplayChangeListener *dcl,
-                           struct DisplayState *s);
-    void (*dpy_gfx_setdata)(DisplayChangeListener *dcl,
-                            struct DisplayState *s);
+    void (*dpy_gfx_switch)(DisplayChangeListener *dcl,
+                           struct DisplayState *s,
+                           struct DisplaySurface *new_surface);
     void (*dpy_gfx_copy)(DisplayChangeListener *dcl,
                          struct DisplayState *s, int src_x, int src_y,
                          int dst_x, int dst_y, int w, int h);