MLCE-530 Add support of int8 weight for UnidirectionalSequenceLstm
 to Ref backend and armnn delegate

Signed-off-by: Narumol Prangnawarat <narumol.prangnawarat@arm.com>
Change-Id: I203d0029c12221228ffe229acda3c90594394e9b
diff --git a/src/backends/reference/RefLayerSupport.cpp b/src/backends/reference/RefLayerSupport.cpp
index 2603371..5eba3e5 100644
--- a/src/backends/reference/RefLayerSupport.cpp
+++ b/src/backends/reference/RefLayerSupport.cpp
@@ -2317,9 +2317,10 @@
         DataType::Float32
     };
 
-    std::array<DataType, 1> supportedWeightTypes =
+    std::array<DataType, 2> supportedWeightTypes =
     {
-        DataType::Float32
+        DataType::Float32,
+        DataType::QAsymmS8
     };
 
     // check inputs and outputs