InitializeGraphicsMode. The update of this register would cause the xorg-cirrus driver to mis-detect the size of video memory for the QEMU cirrus video device. git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@8690 6f19259b-4bc3-4df7-8a09-765794883524