Add the missing CRYPTO_ALG_ASYNC flag since hisilizon zip driver
works asynchronously.

Cc: Zhou Wang <wangzhou1@hisilicon.com>
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
Acked-by: Yang Shen <shenyang39@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>