Bootloader does not expect FSP modifies GDTR and segment selectors, update FSP entry/exit code to preserve these registers. Signed-off-by: Ray Ni <ray.ni@intel.com> Cc: Chasel Chiu <chasel.chiu@intel.com> Cc: Nate DeSimone <nathaniel.l.desimone@intel.com> Cc: Star Zeng <star.zeng@intel.com> Cc: Ted Kuo <ted.kuo@intel.com> Cc: Ashraf Ali S <ashraf.ali.s@intel.com>