CryptoPkg: BaseCryptLib: Update Salt length requirement for RSA-PSS scheme.

CryptoPkg: BaseCryptLib: Update Salt length requirement for RSA-PSS scheme.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3455

Enforce salt length to be equal to digest length for RSA-PSS
encoding scheme.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Xiaoyu Lu <xiaoyux.lu@intel.com>
Cc: Guomin Jiang <guomin.jiang@intel.com>
Signed-off-by: Sachin Agrawal <sachin.agrawal@intel.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>