crypto: stm32 - remove unnecessary alignmask

The stm32 crc32 algorithms set a nonzero alignmask, but they don't seem
to actually need it.  Their ->update function already has code that
handles aligning the data to the same alignment that the alignmask
specifies, their ->setkey function already uses get_unaligned_le32(),
and their ->final function already uses put_unaligned_le32().
Therefore, stop setting the alignmask.  This will allow these algorithms
to keep being registered after alignmask support is removed from shash.

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