crypto: skcipher - Add crypto_skcipher_has_setkey

This patch adds a way for skcipher users to determine whether a key
is required by a transform.

Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/include/crypto/skcipher.h b/include/crypto/skcipher.h
index d8dd41f..fd8742a 100644
--- a/include/crypto/skcipher.h
+++ b/include/crypto/skcipher.h
@@ -61,6 +61,8 @@
 	unsigned int ivsize;
 	unsigned int reqsize;
 
+	bool has_setkey;
+
 	struct crypto_tfm base;
 };
 
@@ -305,6 +307,11 @@
 	return tfm->setkey(tfm, key, keylen);
 }
 
+static inline bool crypto_skcipher_has_setkey(struct crypto_skcipher *tfm)
+{
+	return tfm->has_setkey;
+}
+
 /**
  * crypto_skcipher_reqtfm() - obtain cipher handle from request
  * @req: skcipher_request out of which the cipher handle is to be obtained