UPSTREAM: crypto: blake2s - define shash_alg structs using macros

The shash_alg structs for the four variants of BLAKE2s are identical
except for the algorithm name, driver name, and digest size.  So, avoid
code duplication by using a macro to define these structs.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

(cherry picked from commit 0d396058f92ae7e5ac62839fed54bc2bba630ab5)
Bug: 152722841
Bug: 178411248
Change-Id: I32b3a6c035b18f063ad0e03c43171091ca1490a8
Signed-off-by: Eric Biggers <ebiggers@google.com>