Bluetooth: samples/mesh_demo: Add dummy provisioning

Some of the provisoning routines, such as node reset assume that we
have a valid bt_mesh_prov pointer.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/samples/bluetooth/mesh_demo/src/main.c b/samples/bluetooth/mesh_demo/src/main.c
index 6181fa8..c7d75f7 100644
--- a/samples/bluetooth/mesh_demo/src/main.c
+++ b/samples/bluetooth/mesh_demo/src/main.c
@@ -167,6 +167,12 @@
 	board_play("100C100D100E100F100G100A100H");
 }
 
+static const u8_t dev_uuid[16] = { 0xdd, 0xdd };
+
+static const struct bt_mesh_prov prov = {
+	.uuid = dev_uuid,
+};
+
 static void bt_ready(int err)
 {
 	if (err) {
@@ -176,7 +182,7 @@
 
 	printk("Bluetooth initialized\n");
 
-	err = bt_mesh_init(NULL, &comp);
+	err = bt_mesh_init(&prov, &comp);
 	if (err) {
 		printk("Initializing mesh failed (err %d)\n", err);
 		return;