crypto: arm64 - Consistently enable extension

Currently most of the crypto files enable the crypto extension using the
.arch directive but crct10dif-ce-core.S uses .cpu instead. Move that over
to .arch for consistency.

Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>