event: Convert arch_cpu_init_dm() to use events

Instead of a special function, send an event after driver model is inited
and adjust the boards which use this function.

Signed-off-by: Simon Glass <sjg@chromium.org>

common/event.c

@@ -26,6 +26,7 @@ const char *const type_name[] = {
 	"test",
 
 	/* Events related to driver model */
+	"dm_post_init",
 	"dm_pre_probe",
 	"dm_post_probe",
 	"dm_pre_remove",