IVGCVSW-7568 Implement Sub ElementwiseBinary operator GpuFsa

* Added support for Gpu Sub operator
* Added unit tests

Signed-off-by: John Mcloughlin <john.mcloughlin@arm.com>
Change-Id: I1efaa485772a3716e3781566843bd50bd9bab811
diff --git a/src/backends/gpuFsa/test/GpuFsaLayerSupportTests.cpp b/src/backends/gpuFsa/test/GpuFsaLayerSupportTests.cpp
index 49ddade..9d4b3b9 100644
--- a/src/backends/gpuFsa/test/GpuFsaLayerSupportTests.cpp
+++ b/src/backends/gpuFsa/test/GpuFsaLayerSupportTests.cpp
@@ -81,4 +81,24 @@
     CHECK(supported);
 }
 
+TEST_CASE("IsLayerSupportedGpuFsaElementWiseBinarySub")
+{
+    TensorInfo input0Info({ 2, 2 }, DataType::Float32);
+    TensorInfo input1Info({ 2, 2 }, DataType::Float32);
+    TensorInfo outputInfo({ 2, 2 }, DataType::Float32);
+
+    ElementwiseBinaryDescriptor desc;
+    desc.m_Operation = BinaryOperation::Sub;
+
+    GpuFsaLayerSupport supportChecker;
+    std::string reasonIfNotSupported;
+    auto supported = supportChecker.IsLayerSupported(LayerType::ElementwiseBinary,
+                                                     {input0Info, input1Info, outputInfo},
+                                                     desc,
+                                                     EmptyOptional(),
+                                                     EmptyOptional(),
+                                                     reasonIfNotSupported);
+    CHECK(supported);
+}
+
 }
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