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/GpuFsaEndToEndTests.cpp b/src/backends/gpuFsa/test/GpuFsaEndToEndTests.cpp
index 9972b24..26c7cb8 100644
--- a/src/backends/gpuFsa/test/GpuFsaEndToEndTests.cpp
+++ b/src/backends/gpuFsa/test/GpuFsaEndToEndTests.cpp
@@ -45,4 +45,15 @@
     ElementwiseBinarySimple3DEndToEnd<armnn::DataType::Float16>(gpuFsaDefaultBackends, BinaryOperation::Add);
 }
 
+// ElementwiseBinary Sub
+TEST_CASE("GpuFsaElementwiseBinarySubTestFloat32")
+{
+    ElementwiseBinarySimple3DEndToEnd<armnn::DataType::Float32>(gpuFsaDefaultBackends, BinaryOperation::Sub);
+}
+
+TEST_CASE("GpuFsaElementwiseBinarySubTestFloat16")
+{
+    ElementwiseBinarySimple3DEndToEnd<armnn::DataType::Float16>(gpuFsaDefaultBackends, BinaryOperation::Sub);
+}
+
 }