CryptoPkg: Add HMAC-SHA256 cipher support

Add new HMAC-SHA256 cipher support in CryptoPkg to meet more security
and industry requirements,

and update Cryptest utility to include new HMAC-SHA256 test case.

Cc: Ting Ye <ting.ye@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Qin Long <qin.long@intel.com>
Reviewed-by: Ting Ye <ting.ye@intel.com>

CryptoPkg/Library/BaseCryptLib/PeiCryptLib.inf

@@ -7,13 +7,13 @@
 #  buffer overflow or integer overflow.
 #
 #  Note: MD4 Digest functions, SHA-384 Digest functions, SHA-512 Digest functions,
-#  HMAC-MD5 functions, HMAC-SHA1 functions, AES/TDES/ARC4 functions, RSA external 
+#  HMAC-MD5 functions, HMAC-SHA1/SHA256 functions, AES/TDES/ARC4 functions, RSA external
 #  functions, PKCS#7 SignedData sign functions, Diffie-Hellman functions, X.509 
 #  certificate handler functions, authenticode signature verification functions, 
 #  PEM handler functions, and pseudorandom number generator functions are not 
 #  supported in this instance.
 #
-#  Copyright (c) 2010 - 2014, Intel Corporation. All rights reserved.<BR>
+#  Copyright (c) 2010 - 2016, Intel Corporation. All rights reserved.<BR>
 #  This program and the accompanying materials
 #  are licensed and made available under the terms and conditions of the BSD License
 #  which accompanies this distribution.  The full text of the license may be found at
@@ -47,6 +47,7 @@
   Hash/CryptSha512Null.c
   Hmac/CryptHmacMd5Null.c
   Hmac/CryptHmacSha1Null.c
+  Hmac/CryptHmacSha256Null.c
   Cipher/CryptAesNull.c
   Cipher/CryptTdesNull.c
   Cipher/CryptArc4Null.c