Verify the register address in the FADT. TEST=Build and run on Galileo Gen2 when the FADT was not present. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com> Reviewed-by: Erik Bjorge <erik.c.bjorge@intel.com> Reviewed-by: Prince Agyeman <prince.agyeman@intel.com>