[LITE][OPENCL][Image] fix concat 3dims issue ,success nanoyolo ,test=… (#3029)

* [LITE][OPENCL][Image] fix concat 3dims issue ,success nanoyolo ,test=develop

* [LITE][OPENCL][Image] fix concat 3dims issue ,success nanoyolo,remove debug codes ,test=develop

lite/kernels/opencl/concat_image_compute.cc

@@ -53,6 +53,17 @@ class ConcatComputeImage : public KernelLite<TARGET(kOpenCL),
     auto in_dims = inputs[0]->dims();
     axis_size_ = out_dims[axis];
     axis_ = axis;
+    if (out_dims.size() < 4) {
+      if (out_dims.size() - axis == 1) {
+        // width
+        width_ = out_dims[1];  // c
+        flag_ = 3;
+      } else {
+        // height
+        width_ = out_dims[0];  // n
+        flag_ = 2;
+      }
+    } else {
       switch (axis_) {
         case 0:
           width_ = out_dims[2];  // h
@@ -74,6 +85,8 @@ class ConcatComputeImage : public KernelLite<TARGET(kOpenCL),
         default:
           printf("this axis: %d does not support \n", axis_);
       }
+    }
+
     for (int i = 1; i < inputs.size(); i++) {
       auto dims = inputs[i]->dims();
       // auto flag = CHECK_EQ_OR_FALSE(in_dims.size(), dims.size());