Bluetooth: Mesh: Fix add model group address to sub list

When low power node reset, should add group address to
friend subscription list.

Fixes: zephyrproject-rtos#24311

Signed-off-by: Lingao Meng <mengabc1086@gmail.com>

subsys/bluetooth/mesh/cfg_srv.c

@@ -1262,6 +1262,9 @@ static size_t mod_sub_list_clear(struct bt_mesh_model *mod)
 	/* Unref stored labels related to this model */
 	for (i = 0, clear_count = 0; i < ARRAY_SIZE(mod->groups); i++) {
 		if (mod->groups[i] != BT_MESH_ADDR_UNASSIGNED) {
+			if (IS_ENABLED(CONFIG_BT_MESH_LOW_POWER)) {
+				bt_mesh_lpn_group_del(&mod->groups[i], 1);
+			}
 			mod->groups[i] = BT_MESH_ADDR_UNASSIGNED;
 			clear_count++;
 		}

subsys/bluetooth/mesh/settings.c

@@ -32,6 +32,7 @@
 #include "foundation.h"
 #include "proxy.h"
 #include "settings.h"
+#include "lpn.h"
 
 /* Tracking of what storage changes are pending for App and Net Keys. We
  * track this in a separate array here instead of within the respective
@@ -1097,6 +1098,16 @@ static void commit_mod(struct bt_mesh_model *mod, struct bt_mesh_elem *elem,
 			k_delayed_work_submit(&mod->pub->timer, ms);
 		}
 	}
+
+	if (!IS_ENABLED(CONFIG_BT_MESH_LOW_POWER)) {
+		return;
+	}
+
+	for (int i = 0; i < ARRAY_SIZE(mod->groups); i++) {
+		if (mod->groups[i] != BT_MESH_ADDR_UNASSIGNED) {
+			bt_mesh_lpn_group_add(mod->groups[i]);
+		}
+	}
 }
 
 static int mesh_commit(void)