netfilter: Use header-y instead of unifdef-y

Index: nf-next-2.6/include/linux/netfilter/Kbuild
===================================================================
@@ -1,8 +1,14 @@
+header-y += nf_conntrack_common.h
+header-y += nf_conntrack_ftp.h
 header-y += nf_conntrack_sctp.h
+header-y += nf_conntrack_tcp.h
 header-y += nf_conntrack_tuple_common.h
+header-y += nfnetlink.h
+header-y += nfnetlink_compat.h
 header-y += nfnetlink_conntrack.h
 header-y += nfnetlink_log.h
 header-y += nfnetlink_queue.h
+header-y += x_tables.h
 header-y += xt_CHECKSUM.h
 header-y += xt_CLASSIFY.h
 header-y += xt_CONNMARK.h

@@ -41,7 +47,9 @@ header-y += xt_mark.h
 header-y += xt_multiport.h
 header-y += xt_osf.h
 header-y += xt_owner.h
+header-y += xt_physdev.h
 header-y += xt_pkttype.h
+header-y += xt_policy.h
 header-y += xt_quota.h
 header-y += xt_rateest.h
 header-y += xt_realm.h

@@ -54,12 +62,3 @@ header-y += xt_tcpmss.h
 header-y += xt_tcpudp.h
 header-y += xt_time.h
 header-y += xt_u32.h
-
-unifdef-y += nf_conntrack_common.h
-unifdef-y += nf_conntrack_ftp.h
-unifdef-y += nf_conntrack_tcp.h
-unifdef-y += nfnetlink.h
-unifdef-y += nfnetlink_compat.h
-unifdef-y += x_tables.h
-unifdef-y += xt_physdev.h
-unifdef-y += xt_policy.h