IVGCVSW-2874 Add DequantizeLayer and no-op factory method

*Add Dequantize layer to the frontend
*Add Serializer and Deserializer for Dequantize

Change-Id: Ide2647b9e0348d599deb97e61ca4bf66e2f17fc0
Signed-off-by: Nattapat Chaimanowong <nattapat.chaimanowong@arm.com>
diff --git a/src/armnnSerializer/ArmnnSchema.fbs b/src/armnnSerializer/ArmnnSchema.fbs
index 7ac8359..3aa644d 100644
--- a/src/armnnSerializer/ArmnnSchema.fbs
+++ b/src/armnnSerializer/ArmnnSchema.fbs
@@ -117,7 +117,8 @@
     Splitter = 32,
     DetectionPostProcess = 33,
     Lstm = 34,
-    Quantize = 35
+    Quantize = 35,
+    Dequantize = 36
 }
 
 // Base layer table to be used as part of other layers
@@ -519,6 +520,10 @@
     inputParams:LstmInputParams;
 }
 
+table DequantizeLayer {
+    base:LayerBase;
+}
+
 union Layer {
     ActivationLayer,
     AdditionLayer,
@@ -555,7 +560,8 @@
     SplitterLayer,
     DetectionPostProcessLayer,
     LstmLayer,
-    QuantizeLayer
+    QuantizeLayer,
+    DequantizeLayer
 }
 
 table AnyLayer {