Allow for native timer (cycle level) integration

for MPI_Wtime and MPI_Wtick.

ompi/mpi/c/wtick.c

@@ -40,7 +40,9 @@ double MPI_Wtick(void)
 {
     OPAL_CR_NOOP_PROGRESS();
 
-#if OPAL_TIMER_USEC_NATIVE
+#if OPAL_TIMER_CYCLE_NATIVE
+    return opal_timer_base_get_freq();
+#elif OPAL_TIMER_USEC_NATIVE
     return 0.000001;
 #else
     /* Otherwise, we already return usec precision. */

ompi/mpi/c/wtime.c

@@ -40,7 +40,9 @@ double MPI_Wtime(void)
 {
     double wtime;
 
-#if OPAL_TIMER_USEC_NATIVE
+#if OPAL_TIMER_CYCLE_NATIVE
+    wtime = ((double) opal_timer_base_get_cycles()) / opal_timer_base_get_freq();
+#elif OPAL_TIMER_USEC_NATIVE
     wtime = ((double) opal_timer_base_get_usec()) / 1000000.0;
 #else
     /* Fall back to gettimeofday() if we have nothing else */