crypto: simd - Do not call crypto_alloc_tfm during registration

Algorithm registration is usually carried out during module init,
where as little work as possible should be carried out.  The SIMD
code violated this rule by allocating a tfm, this then triggers a
full test of the algorithm which may dead-lock in certain cases.

SIMD is only allocating the tfm to get at the alg object, which is
in fact already available as it is what we are registering.  Use
that directly and remove the crypto_alloc_tfm call.

Also remove some obsolete and unused SIMD API.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>