crypto: arm64/sm4 - export reusable CE acceleration functions

In the accelerated implementation of the SM4 algorithm using the Crypto
Extension instructions, there are some functions that can be reused in
the upcoming accelerated implementation of the GCM/CCM mode, and the
CBC/CFB encryption is reused in the optimized implementation of SVESM4.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>