IVGCVSW-1843 : replacing trivial arithmetic helpers

Change-Id: Iddf637694f1a3a7ef00f006a41b8044a35c7e73c
diff --git a/Android.mk b/Android.mk
index 9c23736..9c4db74 100644
--- a/Android.mk
+++ b/Android.mk
@@ -128,16 +128,14 @@
         src/armnn/backends/RefWorkloads/RefSoftmaxFloat32Workload.cpp \
         src/armnn/backends/RefWorkloads/RefActivationFloat32Workload.cpp \
         src/armnn/backends/RefWorkloads/RefBatchNormalizationUint8Workload.cpp \
-        src/armnn/backends/RefWorkloads/Multiplication.cpp \
         src/armnn/backends/RefWorkloads/RefMultiplicationUint8Workload.cpp \
         src/armnn/backends/RefWorkloads/RefBaseConstantWorkload.cpp \
         src/armnn/backends/RefWorkloads/RefResizeBilinearFloat32Workload.cpp \
         src/armnn/backends/RefWorkloads/RefBatchNormalizationFloat32Workload.cpp \
         src/armnn/backends/RefWorkloads/Broadcast.cpp \
-        src/armnn/backends/RefWorkloads/Addition.cpp \
+        src/armnn/backends/RefWorkloads/ArithmeticFunction.cpp \
         src/armnn/backends/RefWorkloads/RefAdditionUint8Workload.cpp \
         src/armnn/backends/RefWorkloads/RefAdditionFloat32Workload.cpp \
-        src/armnn/backends/RefWorkloads/Subtraction.cpp \
         src/armnn/backends/RefWorkloads/RefSubtractionUint8Workload.cpp \
         src/armnn/backends/RefWorkloads/RefSubtractionFloat32Workload.cpp \
         src/armnn/backends/RefWorkloads/RefFakeQuantizationFloat32Workload.cpp \
@@ -170,7 +168,6 @@
         src/armnn/backends/RefWorkloads/RefPermuteWorkload.cpp \
         src/armnn/backends/RefWorkloads/RefConvertFp16ToFp32Workload.cpp \
         src/armnn/backends/RefWorkloads/RefConvertFp32ToFp16Workload.cpp \
-        src/armnn/backends/RefWorkloads/Division.cpp \
         src/armnn/backends/RefWorkloads/RefDivisionFloat32Workload.cpp \
         src/armnn/backends/RefWorkloads/RefDivisionUint8Workload.cpp \
         src/armnn/backends/MemCopyWorkload.cpp \