arm_compute v18.01

Change-Id: I9bfa178c2e38bfd5fc812e62aab6760d87748e05
diff --git a/tests/validation/reference/ConvolutionLayer.cpp b/tests/validation/reference/ConvolutionLayer.cpp
index 1066411..567fac0 100644
--- a/tests/validation/reference/ConvolutionLayer.cpp
+++ b/tests/validation/reference/ConvolutionLayer.cpp
@@ -210,7 +210,7 @@
 
     acc = asymm_rounding_divide_by_pow2(asymm_int_mult(acc, output_multiplier), output_shift);
     acc += output_offset;
-    acc = clamp<int32_t>(acc, 0, 255);
+    acc = utility::clamp<int32_t>(acc, 0, 255);
 
     // Store the result
     *out_ptr = acc;