[IPSEC] ESP: Use block ciphers where applicable

This patch converts IPSec/ESP to use the new block cipher type where
applicable.  Similar to the HMAC conversion, existing algorithm names
have been kept for compatibility.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/net/ipv6/Kconfig b/net/ipv6/Kconfig
index e923d4d..0ba06c0 100644
--- a/net/ipv6/Kconfig
+++ b/net/ipv6/Kconfig
@@ -77,6 +77,7 @@
 	select CRYPTO
 	select CRYPTO_HMAC
 	select CRYPTO_MD5
+	select CRYPTO_CBC
 	select CRYPTO_SHA1
 	select CRYPTO_DES
 	---help---