ipv6: Provide ipv6 version of "disable_policy" sysctl

This provides equivalent functionality to the existing ipv4
"disable_policy" systcl. ie. Allows IPsec processing to be skipped
on terminating packets on a per-interface basis.

Signed-off-by: David Forster <dforster@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 71be5b3..f0d79bd 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -70,6 +70,7 @@ struct ipv6_devconf {
 #endif
 	__u32		enhanced_dad;
 	__u32		addr_gen_mode;
+	__s32		disable_policy;
 
 	struct ctl_table_header *sysctl_header;
 };