add Pkcs7Sign.exe and related pem file into BinaryFiles.txt for build server to automatically build the binary win32 files. Cc: Liming Gao <liming.gao@intel.com> CC: Erik Bjorge <erik.c.bjorge@intel.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Yonghong Zhu <yonghong.zhu@intel.com> Reviewed-by: Erik Bjorge <erik.c.bjorge@intel.com>