IVGCVSW-6312 Support pre-importing inputs

Signed-off-by: Finn Williams <Finn.Williams@arm.com>
Change-Id: Ifc5e6f2e36767cb2a5cbf281d40ec9989b581abc
diff --git a/include/armnn/Types.hpp b/include/armnn/Types.hpp
index 0b7b941..c3b439a 100644
--- a/include/armnn/Types.hpp
+++ b/include/armnn/Types.hpp
@@ -265,6 +265,7 @@
 
 /// Type of identifiers for bindable layers (inputs, outputs).
 using LayerBindingId = int;
+using ImportedInputId = unsigned int;
 
 class PermutationVector
 {