arch: arm: cortex_m: Add sys_trace_idle_exit calls

Add calls to sys_trace_idle_exit when leaving idle state. It is
used to track CPU load.

Signed-off-by: Krzysztof Chruściński <krzysztof.chruscinski@nordicsemi.no>

Author: nordic-krch

arch/arm/core/cortex_m/cpu_idle.c

@@ -98,6 +98,9 @@ void arch_cpu_idle(void)
 
 	SLEEP_IF_ALLOWED(__WFI);
 
+#if defined(CONFIG_TRACING)
+	sys_trace_idle_exit();
+#endif
 	__enable_irq();
 	__ISB();
 }
@@ -137,6 +140,10 @@ void arch_cpu_atomic_idle(unsigned int key)
 
 	SLEEP_IF_ALLOWED(__WFE);
 
+#if defined(CONFIG_TRACING)
+	sys_trace_idle_exit();
+#endif
+
 	arch_irq_unlock(key);
 #if defined(CONFIG_ARMV7_M_ARMV8_M_MAINLINE)
 	__enable_irq();