[CRYPTO] skcipher: Create default givcipher instances

This patch makes crypto_alloc_ablkcipher/crypto_grab_skcipher always
return algorithms that are capable of generating their own IVs through
givencrypt and givdecrypt.  Each algorithm may specify its default IV
generator through the geniv field.

For algorithms that do not set the geniv field, the blkcipher layer will
pick a default.  Currently it's chainiv for synchronous algorithms and
eseqiv for asynchronous algorithms.  Note that if these wrappers do not
work on an algorithm then that algorithm must specify its own geniv or
it can't be used at all.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index fa7afa9..835dcaf 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -561,13 +561,8 @@
 	return mask;
 }
 
-static inline struct crypto_ablkcipher *crypto_alloc_ablkcipher(
-	const char *alg_name, u32 type, u32 mask)
-{
-	return __crypto_ablkcipher_cast(
-		crypto_alloc_base(alg_name, crypto_skcipher_type(type),
-				  crypto_skcipher_mask(mask)));
-}
+struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name,
+						  u32 type, u32 mask);
 
 static inline struct crypto_tfm *crypto_ablkcipher_tfm(
 	struct crypto_ablkcipher *tfm)