Adding example dragonfly config file

src/network-workloads/conf/modelnet-mpi-test-dfly-amg-216.conf

+LPGROUPS
+{
+   MODELNET_GRP
+   {
+      repetitions="264";
+      nw-lp="4";
+      modelnet_dragonfly="4";
+      modelnet_dragonfly_router="1";
+   }
+}
+PARAMS
+{
+   packet_size="512";
+   modelnet_order=( "dragonfly", "dragonfly_router");
+   # scheduler options
+   modelnet_scheduler="fcfs";
+   chunk_size="256";
+   # modelnet_scheduler="round-robin";
+   num_routers="8";
+   local_vc_size="16384";
+   global_vc_size="32768";
+   cn_vc_size="16384";
+   local_bandwidth="5.25";
+   global_bandwidth="4.7";
+   cn_bandwidth="5.25";
+   message_size="560";
+   routing="adaptive";
+}