[CRYPTO] api: Add async blkcipher type

This patch adds the mid-level interface for asynchronous block ciphers.
It also includes a generic queueing mechanism that can be used by other
asynchronous crypto operations in future.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/Makefile b/crypto/Makefile
index 12f93f5..3820d4c 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -8,6 +8,7 @@
 crypto_algapi-objs := algapi.o $(crypto_algapi-y)
 obj-$(CONFIG_CRYPTO_ALGAPI) += crypto_algapi.o
 
+obj-$(CONFIG_CRYPTO_ABLKCIPHER) += ablkcipher.o
 obj-$(CONFIG_CRYPTO_BLKCIPHER) += blkcipher.o
 
 crypto_hash-objs := hash.o