[IPSEC]: Add compatibility algorithm name support

This patch adds a compatibility name field for each IPsec algorithm.  This
is needed when parameterised algorithms are used.  For example, "md5" will
become "hmac(md5)", and "aes" will become "cbc(aes)".

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 10396b4..e9114e4 100644
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -854,6 +854,7 @@
 
 struct xfrm_algo_desc {
 	char *name;
+	char *compat;
 	u8 available:1;
 	union {
 		struct xfrm_algo_auth_info auth;