kernel: Disable tick handling when !MULTITHREADING

The kernel timer subsystem isn't part of the !MULTITHREADING
environment (no threads to wake up, though in principle it should be
possible to support timeout callbacks with some work in the future).
Protect it against platforms that select this but still enable a timer
driver.

Signed-off-by: Andy Ross <[email protected]>

Author: Andy Ross

include/drivers/system_timer.h

@@ -65,8 +65,13 @@ extern int sys_clock_device_ctrl(struct device *device,
 #endif
 
 extern s32_t _sys_idle_elapsed_ticks;
+
+#ifdef CONFIG_MULTITHREADING
 #define _sys_clock_tick_announce() \
 		_nano_sys_clock_tick_announce(_sys_idle_elapsed_ticks)
+#else
+#define _sys_clock_tick_announce() /**/
+#endif
 
 /**
  * @brief Account for the tick due to the timer interrupt