IVGCVSW-6469 Add MirrorPad FrontEnd and Ref Support

 * Added PaddingMode enum to PaddingDescriptor to enable Symmetric and
   Reflect padding.
 * Added Symmetric and Reflect Ref implementation.
 * Added Serializer & Deserializer support.
 * Added unit tests.

Signed-off-by: Matthew Sloyan <matthew.sloyan@arm.com>
Change-Id: I4bed907b31742b32ccefe5e8ca39a6f1e5bd9dee
diff --git a/src/armnnSerializer/SerializerUtils.hpp b/src/armnnSerializer/SerializerUtils.hpp
index 5517986..07cdc2a 100644
--- a/src/armnnSerializer/SerializerUtils.hpp
+++ b/src/armnnSerializer/SerializerUtils.hpp
@@ -27,6 +27,8 @@
 
 armnnSerializer::PaddingMethod GetFlatBufferPaddingMethod(armnn::PaddingMethod paddingMethod);
 
+armnnSerializer::PaddingMode GetFlatBufferPaddingMode(armnn::PaddingMode paddingMode);
+
 armnnSerializer::NormalizationAlgorithmChannel GetFlatBufferNormalizationAlgorithmChannel(
     armnn::NormalizationAlgorithmChannel normalizationAlgorithmChannel);