arm64: dts: broadcom: bcm4908: Move reboot syscon out of bus

This fixes following error for every bcm4908 DTS file:
bus@ff800000: reboot: {'type': 'object'} is not allowed for {'compatible': ['syscon-reboot'], 'regmap': [[15]], 'offset': [[52]], 'mask': [[1]]}
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

arch/arm64/boot/dts/broadcom/bcm4908/bcm4908.dtsi

@@ -326,12 +326,12 @@ reset-controller@2644 {
 				#reset-cells = <1>;
 			};
 		};
+	};
 
-		reboot {
-			compatible = "syscon-reboot";
-			regmap = <&timer>;
-			offset = <0x34>;
-			mask = <1>;
-		};
+	reboot {
+		compatible = "syscon-reboot";
+		regmap = <&timer>;
+		offset = <0x34>;
+		mask = <1>;
 	};
 };