[CRYPTO] authenc: Add missing Kconfig dependency on BLKCIPHER

The authenc algorithm requires BLKCIPHER to be present.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/Kconfig

@@ -575,6 +575,7 @@ config CRYPTO_TEST
 config CRYPTO_AUTHENC
 	tristate "Authenc support"
 	select CRYPTO_AEAD
+	select CRYPTO_BLKCIPHER
 	select CRYPTO_MANAGER
 	select CRYPTO_HASH
 	help