pm: rt6xx: Enable OS Timer as wakeup source

Enable os_timer as a wakeup-source in the board
dts file.

Signed-off-by: Mahesh Mahadevan <[email protected]>

Author: mmahadevan108

boards/arm/mimxrt685_evk/mimxrt685_evk_cm33.dts

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, NXP
+ * Copyright (c) 2020-2023, NXP
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -144,6 +144,7 @@
  */
 &os_timer {
 	status = "okay";
+	wakeup-source;
 };
 
 &rtc {