crypto: arm64/sm4-ce - Make dependent on sm4 library instead of sm4-generic

SM4 library is abstracted from sm4-generic algorithm, sm4-ce can depend on
the SM4 library instead of sm4-generic, and some functions in sm4-generic
do not need to be exported.

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