IVGCVSW-2886 Add logging for driver backends

Change-Id: Ie46d78e56922dd14dbaedfb314c8412a49c5a08c
Signed-off-by: Nattapat Chaimanowong <nattapat.chaimanowong@arm.com>
diff --git a/ArmnnDevice.cpp b/ArmnnDevice.cpp
index b807cfa..60bfa74 100644
--- a/ArmnnDevice.cpp
+++ b/ArmnnDevice.cpp
@@ -12,9 +12,25 @@
 #include <log/log.h>
 
 #include <memory>
+#include <string>
 
 using namespace android;
 
+namespace
+{
+
+std::string GetBackendString(const armnn_driver::DriverOptions& options)
+{
+    std::stringstream backends;
+    for (auto&& b : options.GetBackends())
+    {
+        backends << b << " ";
+    }
+    return backends.str();
+}
+
+} // anonymous namespace
+
 namespace armnn_driver
 {
 
@@ -64,6 +80,8 @@
         ALOGE("ArmnnDevice: Failed to setup CL runtime: %s. Device will be unavailable.", error.what());
     }
 #endif
+    ALOGV("ArmnnDevice: Created device with the following backends: %s",
+          GetBackendString(m_Options).c_str());
 }
 
 } // namespace armnn_driver