crypto: doc - remove crypto_alloc_ablkcipher

Remove the documentation reference to crypto_alloc_ablkcipher as the API
function call was removed.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/crypto/api-skcipher.rst

@@ -106,9 +106,6 @@ Asynchronous Block Cipher API - Deprecated
 .. kernel-doc:: include/linux/crypto.h
    :doc: Asynchronous Block Cipher API
 
-.. kernel-doc:: include/linux/crypto.h
-   :functions: crypto_alloc_ablkcipher
-
 .. kernel-doc:: include/linux/crypto.h
    :functions: crypto_free_ablkcipher