crypto: export NULL algorithms defines

These defines might be needed by crypto drivers.

Signed-off-by: Horia Geanta <horia.geanta@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/include/crypto/null.h b/include/crypto/null.h
new file mode 100644
index 0000000..b7c864c
--- /dev/null
+++ b/include/crypto/null.h
@@ -0,0 +1,11 @@
+/* Values for NULL algorithms */
+
+#ifndef _CRYPTO_NULL_H
+#define _CRYPTO_NULL_H
+
+#define NULL_KEY_SIZE		0
+#define NULL_BLOCK_SIZE		1
+#define NULL_DIGEST_SIZE	0
+#define NULL_IV_SIZE		0
+
+#endif