IntelFsp2Pkg: Add Fsp22SecCoreS.inf to Dsc.

IntelFsp2Pkg: Add Fsp22SecCoreS.inf to Dsc.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2788

DSC is incomplete according to the established CI policies.
Fsp22SecCoreS.inf needs to be added to the Components section
for completeness.

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: Sean Brogan <sean.brogan@microsoft.com>
Reviewed-by: Nate DeSimone <nathaniel.l.desimone@intel.com>