arm64: dts: broadcom: bcm4908: Fix cpu node for smp boot

Add spin-table enable-method and cpu-release-addr properties for
cpu0 node. This is required by all ARMv8 SoC. Otherwise some
bootloader like u-boot can not update cpu-release-addr and linux
fails to start up secondary cpus.

Fixes: 2961f69f ("arm64: dts: broadcom: add BCM4908 and Asus GT-AC5300 early DTS files")
Signed-off-by: William Zhang <william.zhang@broadcom.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

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

@@ -29,6 +29,8 @@ cpu0: cpu@0 {
 			device_type = "cpu";
 			compatible = "brcm,brahma-b53";
 			reg = <0x0>;
+			enable-method = "spin-table";
+			cpu-release-addr = <0x0 0xfff8>;
 			next-level-cache = <&l2>;
 		};