This new module can be used to compute SM3 message digest of files or
memory blocks according to the specification GM/T 004-2012
Cryptographic Hash Algorithm SM3, published by State Encryption
Management Bureau, China.
- cipher/Makefile.am: Define sm3 module
 - cipher/md.c: Add sm3 spec to the digest list
 - cipher/pubkey-util.c: Add sm3 to the list of known hash name
 - cipher/sm3.c: Implement SM3 hash function
 - configure.ac: Add sm3 to the available digest list
 - src/cipher.h: Declare sm3 function
 - src/gcrypt.h.in: Define GCRY_MD_SM3
 - tests/basic.c: Add sm3 basic test
 - tests/hashtest-256g.in: Enable 256g test with sm3
 - tests/hashtest.c: Define 256g check values for sm3