This patch supports basic gfx passthrough on xen side:
- add a VGA type for gfx passthrough, and get the size of VGA bios
of passthrouged gfx in hvmloader
- add a config option 'gfx_passthru' for gfx passthrough
Signed-off-by: Ben Lin <ben.y.lin@intel.com>
Signed-off-by: Weidong Han <weidong.han@intel.com>