IVGCVSW-8055 Add support for GELU activation function.

* Add support to CpuRef, CpuAcc and GpuAcc
* Add support to tflite parser, classic and opaque tflite delegates
* Add support to serializer and deserializer
* Add Unit tests

Signed-off-by: Teresa Charlin <teresa.charlinreyes@arm.com>
Change-Id: Ibc60ef2ef2a051e6d9af6e15d24c46316ec19de4
diff --git a/docs/05_03_delegate.dox b/docs/05_03_delegate.dox
index 9a40a8a..dde50e1 100644
--- a/docs/05_03_delegate.dox
+++ b/docs/05_03_delegate.dox
@@ -86,6 +86,8 @@
 
 - GATHER_ND
 
+- GELU
+
 - GREATER
 
 - GREATER_EQUAL