lantiq: BTHOMEHUBV5A - use the power event code for the restart button

The restart event code is used in LEDE to trigger a factory reset on
long press as well.

By using the power event code, the restart functionality can be used
without being prone to trigger a factory reset.

Signed-off-by: Mathias Kresin <dev@kresin.me>

target/linux/lantiq/dts/BTHOMEHUBV5A.dts

@@ -158,7 +158,7 @@
 		restart {
 			label = "restart";
 			gpios = <&gpio 39 1>;
-			linux,code = <0x198>;
+			linux,code = <0x74>;
 		};
 	};