embed OvmfVideo.rom into OVMF.fd

embed OvmfVideo.rom into OVMF.fd

This enables qemu to use OVMF with a single -bios option. Based on
<http://lists.xen.org/archives/html/xen-devel/2012-03/msg01992.html>.

v1->v2:
- move xen-devel link from code to commit message
- cover all three FDF files

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
[jordan.l.justen@intel.com: remove vgabios-cirrus.bin from build.sh/README]
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13520 6f19259b-4bc3-4df7-8a09-765794883524