Add PMU prints

Update message handler application to output PMU counters to the log.

Change-Id: Ib6002e7c0035d6736b58eed61a059553083348ce
diff --git a/applications/message_handler/message_handler.cpp b/applications/message_handler/message_handler.cpp
index 585d63c..f6135fc 100644
--- a/applications/message_handler/message_handler.cpp
+++ b/applications/message_handler/message_handler.cpp
@@ -254,6 +254,20 @@
     job.clean();
 
     /*
+     * Print PMU counters
+     */
+
+    const int numEvents = std::min(static_cast<int>(ETHOSU_PMU_Get_NumEventCounters()), ETHOSU_CORE_PMU_MAX);
+
+    for (int i = 0; i < numEvents; i++) {
+        printf("ethos-u : ethosu_pmu_cntr%d : %" PRIu32 "\n", i, rsp.pmu_event_count[i]);
+    }
+
+    if (rsp.pmu_cycle_counter_enable) {
+        printf("ethos-u : cycle_cnt : %" PRIu64 " cycles\n", rsp.pmu_cycle_counter_count);
+    }
+
+    /*
      * Send inference response
      */