SecurityPkg\Tcg2Pei: FV measure performance enhancement

SecurityPkg\Tcg2Pei: FV measure performance enhancement

1. Leverage Pre-Hashed FV PPI to reduce duplicated hash
2. Only measure BFV at the beginning. Other FVs are measured in FVinfo callback with nested
   FV check. https://bugzilla.tianocore.org/show_bug.cgi?id=662

Cc: Long Qin <qin.long@intel.com>
Cc: Yao Jiewen <jiewen.yao@intel.com>
Cc: Sean Brogan <sean.brogan@microsoft.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Chao Zhang <chao.b.zhang@intel.com>
Reviewed-by: Long Qin <qin.long@intel.com>
Reviewed-by: Yao Jiewen <jiewen.yao@intel.com>