crypto: hash: add afalg-backend hash support

Adds afalg-backend hash support: introduces some private APIs
firstly, and then intergrates them into qcrypto_hash_afalg_driver.

Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
diff --git a/crypto/afalgpriv.h b/crypto/afalgpriv.h
index d0941d4..f6550b5 100644
--- a/crypto/afalgpriv.h
+++ b/crypto/afalgpriv.h
@@ -24,6 +24,7 @@
 #endif
 
 #define AFALG_TYPE_CIPHER "skcipher"
+#define AFALG_TYPE_HASH "hash"
 
 #define ALG_OPTYPE_LEN 4
 #define ALG_MSGIV_LEN(len) (sizeof(struct af_alg_iv) + (len))