add arpwatch depend on libpcap

git-svn-id: svn://svn.openwrt.org/openwrt/trunk/openwrt@542 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/Makefile

@@ -54,6 +54,7 @@ clean: $(patsubst %,%-clean,$(package-) $(package-y) $(package-m)) linux-clean
 compile: $(patsubst %,%-compile,$(package-y) $(package-m))
 install: $(patsubst %,%-install,$(package-y))
 
+arpwatch-compile: libpcap-compile
 tcpdump-compile: libpcap-compile
 dropbear-compile: zlib-compile
 openssl-compile: zlib-compile