Fix EltwiseLayerNode and QuantizationLayerNode

- Fixed issue where EltwiseLayerNode would base output shape
  off of first input tensor only
- Allow QuantizationLayerNode to use any quantized data type
  if specified in constructor

Signed-off-by: thecha01 <theo.charalambous@arm.com>
Change-Id: Ib93470316799028cd573592a3d79943493eaa093
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/3737
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Reviewed-by: Manuel Bottini <manuel.bottini@arm.com>
diff --git a/arm_compute/graph/nodes/QuantizationLayerNode.h b/arm_compute/graph/nodes/QuantizationLayerNode.h
index 94c718b..e5d81af 100644
--- a/arm_compute/graph/nodes/QuantizationLayerNode.h
+++ b/arm_compute/graph/nodes/QuantizationLayerNode.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019 Arm Limited.
+ * Copyright (c) 2019-2020 Arm Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -40,6 +40,13 @@
      */
     QuantizationLayerNode(QuantizationInfo out_quant_info);
 
+    /** Constructor
+     *
+     * @param[in] out_quant_info Output quantization info
+     * @param[in] out_data_type  Output data type
+     */
+    QuantizationLayerNode(QuantizationInfo out_quant_info, DataType out_data_type);
+
     // Inherited overridden methods:
     NodeType         type() const override;
     bool             forward_descriptors() override;
@@ -50,6 +57,7 @@
 
 private:
     QuantizationInfo _out_quant_info;
+    DataType         _out_data_type;
 };
 } // namespace graph
 } // namespace arm_compute