IVGCVSW-6515 Restricting CpuRef LSTM tests to run only when CpuRef is enabled

Signed-off-by: Teresa Charlin <teresa.charlinreyes@arm.com>
Change-Id: Icabc39559efd9e621657eb48454fe52155e8c9ff
diff --git a/test/1.2/Lstm.cpp b/test/1.2/Lstm.cpp
index 59d5d38..7a2b394 100644
--- a/test/1.2/Lstm.cpp
+++ b/test/1.2/Lstm.cpp
@@ -7,6 +7,7 @@
 
 using namespace armnn_driver;
 
+#if defined(ARMNNREF_ENABLED)
 DOCTEST_TEST_SUITE("LstmTests_1.2_CpuRef")
 {
 
@@ -36,6 +37,7 @@
     }
 
 }
+#endif
 
 #if defined(ARMCOMPUTECL_ENABLED)
 DOCTEST_TEST_SUITE("LstmTests_1.2_GpuAcc")