Fix building at 5.x.

Submitted by:	Nick Barkas <snb at threerings.net> (maintainer by email)

sysutils/ipmi-kmod/Makefile

@@ -26,10 +26,6 @@ KMODDIR=	/boot/modules
 
 .include <bsd.port.pre.mk>
 
-.if ${OSVERSION} < 600000
-BROKEN=		Does not compile
-.endif
-
 ONLY_FOR_ARCHS=	i386 amd64
 
 # Don't strip module on amd64 systems
@@ -47,6 +43,11 @@ IGNORE=		already in the base system
 IGNORE=		does not support FreeBSD before 5.3
 .endif
 
+# Need to include this extra path on 5.x.
+.if ${OSVERSION} < 600000
+CFLAGS+=	-I@/contrib/dev/acpica
+.endif
+
 do-install:
 	@${MKDIR} ${PREFIX}/include/sys
 	${INSTALL_DATA} ${WRKSRC}/sys/ipmi.h ${PREFIX}/include/sys