tracing: POSIX arch: Trace switch to main thread

Add tracing of the switch to the main thread

Relatest to #13357

Signed-off-by: Alberto Escolar Piedras <[email protected]>

Author: aescolar

arch/posix/core/swap.c

@@ -93,8 +93,13 @@ void _arch_switch_to_main_thread(struct k_thread *main_thread,
 	posix_thread_status_t *ready_thread_ptr =
 			(posix_thread_status_t *)
 			_kernel.ready_q.cache->callee_saved.thread_status;
+
+	z_sys_trace_thread_switched_out();
+
 	_kernel.current = _kernel.ready_q.cache;
 
+	z_sys_trace_thread_switched_in();
+
 	posix_main_thread_start(ready_thread_ptr->thread_idx);
 } /* LCOV_EXCL_LINE */
 #endif