crypto: hisilicon/hpre - add 'CURVE25519' algorithm

Enable 'CURVE25519' algorithm in Kunpeng 930.

Signed-off-by: Meng Yu <yumeng18@huawei.com>
Reviewed-by: Zaibo Xu <xuzaibo@huawei.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>