Add support ElementwiseMax operator in graph API

Signed-off-by: thecha01 <theo.charalambous@arm.com>
Change-Id: I764f1eabb6412350eb719cc755b8777efc7d70a1
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/3736
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
diff --git a/src/graph/backends/CL/CLFunctionsFactory.cpp b/src/graph/backends/CL/CLFunctionsFactory.cpp
index d41da4b..c9d1f6a 100644
--- a/src/graph/backends/CL/CLFunctionsFactory.cpp
+++ b/src/graph/backends/CL/CLFunctionsFactory.cpp
@@ -64,6 +64,7 @@
     using Addition       = CLArithmeticAddition;
     using Subtraction    = CLArithmeticSubtraction;
     using Multiplication = CLPixelWiseMultiplication;
+    using Maximum        = CLElementwiseMax;
 };
 
 /** Collection of CL unary element-wise functions */