IntelFsp2Pkg/SplitFspBin.py: Support rebasing 1.x binary.
    
    REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1308
    
    Support rebasing FSP 1.x binary.
    FSP 1.x has single component in binary so not supported
    by split command and rebase can be done with the same
    command for rebasing FSP-T component in FSP 2.x image.
    
    Test: both FSP 2.x (Kabylake) and FSP 1.x (BroadwellDE) binary
          can be rebased successfully.
    
    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: Star Zeng <star.zeng@intel.com>
    Reviewed-by: Nate DeSimone <nathaniel.l.desimone@intel.com>