fix: Initialize sideband kscan in APPLICATION.

* In order to be sure the rest of the system is fully ready before
  intializing, because init may result in immediate events being
  triggered when used with toggle direct kscan inner devices.

app/src/kscan_sideband_behaviors.c

@@ -173,7 +173,7 @@ static int ksbb_pm_action(const struct device *dev, enum pm_device_action action
     struct ksbb_data ksbb_data_##n = {};                                                           \
     PM_DEVICE_DT_INST_DEFINE(n, ksbb_pm_action);                                                   \
     DEVICE_DT_INST_DEFINE(n, ksbb_init, PM_DEVICE_DT_INST_GET(n), &ksbb_data_##n,                  \
-                          &ksbb_config_##n, POST_KERNEL,                                           \
+                          &ksbb_config_##n, APPLICATION,                                           \
                           CONFIG_ZMK_KSCAN_SIDEBAND_BEHAVIORS_INIT_PRIORITY, &ksbb_api);
 
 DT_INST_FOREACH_STATUS_OKAY(KSBB_INST)