Add Arp Cache dump

Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
diff --git a/cmds/dumpstate/dumpstate.c b/cmds/dumpstate/dumpstate.c
index 78f90a1..adec5a4 100644
--- a/cmds/dumpstate/dumpstate.c
+++ b/cmds/dumpstate/dumpstate.c
@@ -96,6 +96,7 @@
 
     run_command("NETWORK INTERFACES", 10, "netcfg", NULL);
     dump_file("NETWORK ROUTES", "/proc/net/route");
+    dump_file("ARP CACHE", "/proc/net/arp");
 
 #ifdef FWDUMP_bcm4329
     run_command("DUMP WIFI FIRMWARE LOG", 60,