IntelFsp2Pkg/SplitFspBin.py: adopt FSP 2.3 specification.

IntelFsp2Pkg/SplitFspBin.py: adopt FSP 2.3 specification.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3705

FSP 2.3 has updated FSP_INFO_HEADER to support ExtendedImageRevision
and SplitFspBin.py needs to support it.

Also updated script to display integer value basing on length.

Cc: Maurice Ma <maurice.ma@intel.com>
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: Maurice Ma <maurice.ma@intel.com>
Reviewed-by: Nate DeSimone <nathaniel.l.desimone@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>