Move "class OverrideAttribs" to OptRomInfStatement.py to remove "import OptionRom" which may form a circular import: GenFds.OptionRom => GenFds.OptRomInfStatement => GenFds.OptionRom Contributed-under: TianoCore Contribution Agreement 1.1 Cc: Yonghong Zhu <yonghong.zhu@intel.com> Cc: Liming Gao <liming.gao@intel.com> Signed-off-by: Gary Lin <glin@suse.com> Reviewed-by: Jaben Carsey <jaben.carsey@intel.com>