PMU begin and end events

Restore print format for PMU output.

Use begin and end events to enable the PMU cycle counter.

Change-Id: Iaf2d9b78b031f34c0cde0296b4248dea38f19860
diff --git a/applications/message_handler/message_handler.cpp b/applications/message_handler/message_handler.cpp
index f6135fc..817255f 100644
--- a/applications/message_handler/message_handler.cpp
+++ b/applications/message_handler/message_handler.cpp
@@ -260,11 +260,11 @@
     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]);
+        printf("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);
+        printf("ethosu_pmu_cycle_cntr : %" PRIu64 " cycles\n", rsp.pmu_cycle_counter_count);
     }
 
     /*
@@ -424,6 +424,9 @@
 
     // Enable cycle counter
     if (self->currentReq->pmu_cycle_counter_enable) {
+        ETHOSU_PMU_PMCCNTR_CFG_Set_Stop_Event(drv, ETHOSU_PMU_NPU_IDLE);
+        ETHOSU_PMU_PMCCNTR_CFG_Set_Start_Event(drv, ETHOSU_PMU_NPU_ACTIVE);
+
         ETHOSU_PMU_CNTR_Enable(drv, ETHOSU_PMU_CCNT_Msk);
         ETHOSU_PMU_CYCCNT_Reset(drv);
     }