Add TKDNN_MODE variable to the name of the network.

This commit permits to obtain different .rt files for different
precision optimizations of the same network.

Signed-off-by: Davide Sapienza <sapienza.dav@gmail.com>

tests/dla34_cnet/dla34_cnet.cpp

@@ -477,7 +477,7 @@ int main()
     net.print();
 
     //convert network to tensorRT
-    tk::dnn::NetworkRT netRT(&net, "dla34_cnet.rt");
+    tk::dnn::NetworkRT netRT(&net, net.getNetworkRTName("dla34_cnet"));
 
     tk::dnn::dataDim_t dim1 = dim; //input dim
     printCenteredTitle(" CUDNN inference ", '=', 30);