Add Mobilenet2SSDLite test

The new test works both with TensorRT and cuDNN. Preprocessing and
Postprocessing are missing. Add ClippedReLU (for ReLU6), groups for
Conv2d, additional bias for convolution.

Other minors:
-move the timer in the detector to measure all the
processing time for a given frame (both centernet and yolo);
-add int8 flag.

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

src/kernels/activation_relu_ceiling.cu

@@ -0,0 +1,33 @@
+#include "kernels.h"
+
+__global__
+void activation_relu_ceiling(dnnType *input, dnnType *output, int size, const float ceiling) {
+
+    int i = blockDim.x*blockIdx.x + threadIdx.x;
+
+    if(i<size) {    
+        if (input[i]>0)
+        {
+            if (input[i]>ceiling)
+                output[i] = ceiling;
+            else
+                output[i] = input[i];
+        }
+        else
+            output[i] = 0.0f;
+    }
+ }
+
+
+/**
+    Relu ceiling activation function
+*/
+void activationReLUCeilingForward(dnnType* srcData, dnnType* dstData, int size, const float ceiling, cudaStream_t stream)
+{
+    int blocks = (size+255)/256;
+    int threads = 256;
+    
+    activation_relu_ceiling<<<blocks, threads, 0, stream>>>(srcData, dstData, size, ceiling);
+}
+
+