SecurityPkg: Fix spelling errors
https://bugzilla.tianocore.org/show_bug.cgi?id=2265
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Chao Zhang <chao.b.zhang@intel.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
Reviewed-by: Jian J Wang <jian.j.wang@intel.com>