Add if_gre module glue.

sys/modules/if_gre/Makefile

@@ -0,0 +1,22 @@
+# $FreeBSD$
+
+.PATH: ${.CURDIR}/../../net ${.CURDIR}/../../netinet 
+
+KMOD=	if_gre
+SRCS=	if_gre.c ip_gre.c opt_inet.h opt_ns.h opt_atalk.h bpf.h
+
+CLEANFILES+=bpf.h
+
+opt_inet.h:
+	echo "#define INET 1" > ${.TARGET}
+
+opt_ns.h:
+	echo "#define NS 1" > ${.TARGET}
+
+opt_atalk.h:
+	echo "#define NETATALK" > ${.TARGET}
+
+bpf.h:
+	echo "#define NBPF 1" > ${.TARGET}
+
+.include <bsd.kmod.mk>