[arch] factor out the debug_cycle_count to arch specific code

Conflicts:

	arch/arm/ops.S

Change-Id: Id0d9baa3e669cc59822819c797ce913dba1606d6
diff --git a/app/tests/thread_tests.c b/app/tests/thread_tests.c
index acbdfbd..908abc7 100644
--- a/app/tests/thread_tests.c
+++ b/app/tests/thread_tests.c
@@ -221,11 +221,11 @@
 
 	event_wait(&context_switch_event);
 
-	uint count = debug_cycle_count();
+	uint count = arch_cycle_count();
 	for (i = 0; i < iter; i++) {
 		thread_yield();
 	}
-	total_count += debug_cycle_count() - count;
+	total_count += arch_cycle_count() - count;
 	thread_sleep(1000);
 	printf("took %u cycles to yield %d times, %u per yield, %u per yield per thread\n", 
 		total_count, iter, total_count / iter, total_count / iter / thread_count);