IntelFsp2Pkg: FSPI_UPD is not mandatory.

IntelFsp2Pkg: FSPI_UPD is not mandatory.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3993
FSPI_UPD is required only When platforms implemented FSP_I component.
Updated the scripts to allow FSPI_UPD not present scenario.
Also fixed FSP_GLOBAL_DATA structure alignment issue and unnecessary
non-backward compatibility change in previous FSP_I patch.

Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Signed-off-by: Chasel Chiu <chasel.chiu@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>