IVGCVSW-5564 Disable INT16 delegate quant tests on ACL

* Since NEON/CL do not support QSYMM16 for Quantization,
  disabling related tests on both backends and running
  on CpuRef only.

Change-Id: Ifbc44cdfb81f25587ef87af8c44243dd88bb25c3
Signed-off-by: James Conroy <james.conroy@arm.com>
diff --git a/delegate/src/test/QuantizationTest.cpp b/delegate/src/test/QuantizationTest.cpp
index 5466d47..f743f24 100644
--- a/delegate/src/test/QuantizationTest.cpp
+++ b/delegate/src/test/QuantizationTest.cpp
@@ -356,43 +356,37 @@
 
 TEST_CASE ("QUANTIZE_FLOAT32_INT16_GpuAcc_Test")
 {
-    std::vector<armnn::BackendId> backends = { armnn::Compute::GpuAcc,
-                                               armnn::Compute::CpuRef };
+    std::vector<armnn::BackendId> backends = { armnn::Compute::CpuRef };
     QuantizeFloat32Int16Test(backends);
 }
 
 TEST_CASE ("QUANTIZE_FLOAT32_INT16_CpuAcc_Test")
 {
-    std::vector<armnn::BackendId> backends = { armnn::Compute::CpuAcc,
-                                               armnn::Compute::CpuRef };
+    std::vector<armnn::BackendId> backends = { armnn::Compute::CpuRef };
     QuantizeFloat32Int16Test(backends);
 }
 
 TEST_CASE ("QUANTIZE_INT16_INT16_GpuAcc_Test")
 {
-    std::vector<armnn::BackendId> backends = { armnn::Compute::GpuAcc,
-                                               armnn::Compute::CpuRef };
+    std::vector<armnn::BackendId> backends = { armnn::Compute::CpuRef };
     QuantizeInt16Int16Test(backends);
 }
 
 TEST_CASE ("QUANTIZE_INT16_INT16_CpuAcc_Test")
 {
-    std::vector<armnn::BackendId> backends = { armnn::Compute::CpuAcc,
-                                               armnn::Compute::CpuRef };
+    std::vector<armnn::BackendId> backends = { armnn::Compute::CpuRef };
     QuantizeInt16Int16Test(backends);
 }
 
 TEST_CASE ("QUANTIZE_INT16_INT8_GpuAcc_Test")
 {
-    std::vector<armnn::BackendId> backends = { armnn::Compute::GpuAcc,
-                                               armnn::Compute::CpuRef };
+    std::vector<armnn::BackendId> backends = { armnn::Compute::CpuRef };
     QuantizeInt16Int8Test(backends);
 }
 
 TEST_CASE ("QUANTIZE_INT16_INT8_CpuAcc_Test")
 {
-    std::vector<armnn::BackendId> backends = { armnn::Compute::CpuAcc,
-                                               armnn::Compute::CpuRef };
+    std::vector<armnn::BackendId> backends = { armnn::Compute::CpuRef };
     QuantizeInt16Int8Test(backends);
 }