cocoa: Fix VBE function Set Display Start Register a dpy_gfx_setdata callback so that the Cocoa code is notified whenever the screen start address changes. Commit 1d3323d has a similar fix for the VNC UI. Signed-off-by: Henry Harrington <henry.harrington@gmail.com> Cc: qemu-stable@nongnu.org (1.3.x) Signed-off-by: Andreas Färber <andreas.faerber@web.de>