IVGCVSW-3722 Add ArgMinMax to GetLayerAsCString InternalTypes

Signed-off-by: Kevin May <kevin.may@arm.com>
Change-Id: I304aec5c2f83d062a8b0c14d6c8ad01123dc7435
diff --git a/src/armnn/InternalTypes.cpp b/src/armnn/InternalTypes.cpp
index 96af602..460a397 100644
--- a/src/armnn/InternalTypes.cpp
+++ b/src/armnn/InternalTypes.cpp
@@ -17,6 +17,7 @@
         case LayerType::Abs: return "Abs";
         case LayerType::Activation: return "Activation";
         case LayerType::Addition: return "Addition";
+        case LayerType::ArgMinMax: return "ArgMinMax";
         case LayerType::BatchNormalization: return "BatchNormalization";
         case LayerType::BatchToSpaceNd: return "BatchToSpaceNd";
         case LayerType::Concat: return "Concat";