crypto: arm64/aes-neonbs - stop using SIMD helper for skciphers

Calls into the skcipher API can only occur from contexts where the SIMD
unit is available, so there is no need for the SIMD helper.

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