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/src/backends/aclCommon/ArmComputeUtils.hpp b/src/backends/aclCommon/ArmComputeUtils.hpp
index fc59b28..f466ab1 100644
--- a/src/backends/aclCommon/ArmComputeUtils.hpp
+++ b/src/backends/aclCommon/ArmComputeUtils.hpp
@@ -77,6 +77,7 @@
         case ActivationFunction::TanH:          return AclActivationFunction::TANH;
         case ActivationFunction::Elu:           return AclActivationFunction::ELU;
         case ActivationFunction::HardSwish:     return AclActivationFunction::HARD_SWISH;
+        case ActivationFunction::Gelu:          return AclActivationFunction::GELU;
         default:                                throw InvalidArgumentException("Unsupported activation function");
     }
 }