[PATCH] sm3: implement SM3 hash algorithm

[张佳(乾越)]

Hi Werner,

This is the review request for SM3 hash algorithm. Plz see the commit
header and patch for more details.

SM3 hash algorithm is already accepted and supported by TPM 2.0 spec.
So it is necessary to implement this algorithm in a famous open source
software for checking the digest value computed by TPM.

Plz refer to this PR (https://github.com/gpg/libgcrypt/pull/2) for code
review.

Thanks,
Jia