Add Signed32 to debug layer

Signed-off-by: Narumol Prangnawarat <narumol.prangnawarat@arm.com>
Change-Id: Iedfc196bfd18e8280e99a06db68df9c15c8ea835
diff --git a/src/backends/reference/RefLayerSupport.cpp b/src/backends/reference/RefLayerSupport.cpp
index 4767aa0..26a61d4 100644
--- a/src/backends/reference/RefLayerSupport.cpp
+++ b/src/backends/reference/RefLayerSupport.cpp
@@ -496,12 +496,13 @@
 {
     bool supported = true;
 
-    std::array<DataType, 4> supportedTypes =
+    std::array<DataType, 5> supportedTypes =
     {
         DataType::Float16,
         DataType::Float32,
         DataType::QAsymmU8,
-        DataType::QSymmS16
+        DataType::QSymmS16,
+        DataType::Signed32
     };
 
     supported &= CheckSupportRule(TypeAnyOf(input, supportedTypes), reasonIfUnsupported,