IVGCVSW-4511 Add BFloat16 to RefLayerSupport and unit tests

Signed-off-by: Narumol Prangnawarat <narumol.prangnawarat@arm.com>
Change-Id: Ifaae4d5aac468ba927b2c6a4bf31b8c8522aeb2e
diff --git a/src/backends/reference/workloads/RefPadWorkload.cpp b/src/backends/reference/workloads/RefPadWorkload.cpp
index 356f6b1..777682d 100644
--- a/src/backends/reference/workloads/RefPadWorkload.cpp
+++ b/src/backends/reference/workloads/RefPadWorkload.cpp
@@ -33,6 +33,7 @@
     Pad(inputInfo, outputInfo, m_Data.m_Parameters.m_PadList, inputData, outputData, m_Data.m_Parameters.m_PadValue);
 }
 
+template class RefPadWorkload<DataType::BFloat16>;
 template class RefPadWorkload<DataType::Float32>;
 template class RefPadWorkload<DataType::Float16>;
 template class RefPadWorkload<DataType::QAsymmU8>;