netfilter: add missing xt_bpf.h header in installation

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/include/uapi/linux/netfilter/Kbuild b/include/uapi/linux/netfilter/Kbuild
index 08f555f..8b4bd36 100644
--- a/include/uapi/linux/netfilter/Kbuild
+++ b/include/uapi/linux/netfilter/Kbuild
@@ -35,6 +35,7 @@
 header-y += xt_TEE.h
 header-y += xt_TPROXY.h
 header-y += xt_addrtype.h
+header-y += xt_bpf.h
 header-y += xt_cluster.h
 header-y += xt_comment.h
 header-y += xt_connbytes.h