overlays: fsm-demo: Ensure all LEDs are turned off

raspberrypi inclusion
category: feature
bugzilla: 50432

--------------------------------

If the shutdown process is delayed enough to trigger the shutdown
timeout then one or more states in the shutdown sequence might be
skipped. Ensure that all LEDs are turned off regardless by explicitly
doing so in the shutdown state, as an example of good practices.
Signed-off-by: NPhil Elwell <phil@raspberrypi.com>
Signed-off-by: NFang Yafen <yafen@iscas.ac.cn>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

arch/arm/boot/dts/overlays/fsm-demo-overlay.dts

@@ -92,7 +92,7 @@
 
 				shutdown4 {
 					shutdown_state;
-					set = <RED 0>;
+					set = <RED 0>, <AMBER 0>, <GREEN 0>;
 				};
 			};
 	       };