timer_test: set 8 as default steps, use the default in testsuite.at

Change-Id: I5070578e9fe2bdacaad000eaafb8dc5f549d6f3e
diff --git a/tests/timer/timer_test.c b/tests/timer/timer_test.c
index ec85c04..066dc72 100644
--- a/tests/timer/timer_test.c
+++ b/tests/timer/timer_test.c
@@ -54,7 +54,7 @@
 };
 
 /* number of test steps. We add fact(steps) timers in the whole test. */
-#define MAIN_TIMER_NSTEPS	16
+#define MAIN_TIMER_NSTEPS	8
 
 /* time between two steps, in secs. */
 #define TIME_BETWEEN_STEPS	1