[XFRM]: Extract common hashing code into xfrm_hash.[ch]

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/xfrm/Makefile b/net/xfrm/Makefile
index 693aac1..de3c1a6 100644
--- a/net/xfrm/Makefile
+++ b/net/xfrm/Makefile
@@ -2,6 +2,7 @@
 # Makefile for the XFRM subsystem.
 #
 
-obj-$(CONFIG_XFRM) := xfrm_policy.o xfrm_state.o xfrm_input.o xfrm_algo.o
+obj-$(CONFIG_XFRM) := xfrm_policy.o xfrm_state.o xfrm_hash.o \
+		      xfrm_input.o xfrm_algo.o
 obj-$(CONFIG_XFRM_USER) += xfrm_user.o