IVGCVSW-7104: BatchMatMul Serializer/Deserializer Support

  * Updated FlatBuffers schema for BatchMatMul layer type
  * Added Serializer and Deserializer implementations for BatchMatMul
  * Added unit tests for BatchMatMul serialization and deserialization
  * Updated CMakeLists and docs

Signed-off-by: Samuel Yap <samuel.yap@arm.com>
Change-Id: Iad63afbd036a3eb648683eb7416a475561aa20cb
diff --git a/docs/05_02_deserializer_serializer.dox b/docs/05_02_deserializer_serializer.dox
index 6cfaf29..c36e010 100644
--- a/docs/05_02_deserializer_serializer.dox
+++ b/docs/05_02_deserializer_serializer.dox
@@ -22,6 +22,7 @@
 - Activation
 - Addition
 - ArgMinMax
+- BatchMatMul
 - BatchToSpaceNd
 - BatchNormalization
 - Cast
@@ -114,6 +115,7 @@
 - Activation
 - Addition
 - ArgMinMax
+- BatchMatMul
 - BatchToSpaceNd
 - BatchNormalization
 - Cast