FSP binary potentially can include X64 drivers to simplify implementation or support new features so update SplitFspBin.py to support x64 image headers. Cc: Jiewen Yao <Jiewen.yao@intel.com> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Chasel Chiu <chasel.chiu@intel.com> Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>