lib/crypto: x86/sm3: Migrate optimized code into library

lib/crypto: x86/sm3: Migrate optimized code into library

Instead of exposing the x86-optimized SM3 code via an x86-specific
crypto_shash algorithm, instead just implement the sm3_blocks() library
function.  This is much simpler, it makes the SM3 library functions be
x86-optimized, and it fixes the longstanding issue where the
x86-optimized SM3 code was disabled by default.  SM3 still remains
available through crypto_shash, but individual architectures no longer
need to handle it.

Tweak the prototype of sm3_transform_avx() to match what the library
expects, including changing the block count to size_t.  Note that the
assembly code actually already treated this argument as size_t.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260321040935.410034-10-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>