[MLSXFRM]: Add security sid to flowi

This adds security to flow key for labeling of flows as also to allow
for making flow cache lookups based on the security label seemless.

Signed-off-by: Venkat Yekkirala <vyekkirala@TrustedCS.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/flow.h b/include/net/flow.h
index 04d89f7..1cee5a8 100644
--- a/include/net/flow.h
+++ b/include/net/flow.h
@@ -78,6 +78,7 @@
 #define fl_icmp_type	uli_u.icmpt.type
 #define fl_icmp_code	uli_u.icmpt.code
 #define fl_ipsec_spi	uli_u.spi
+	__u32           secid;	/* used by xfrm; see secid.txt */
 } __attribute__((__aligned__(BITS_PER_LONG/8)));
 
 #define FLOW_DIR_IN	0