ARM: rockchip: convert smp bringup to CPU_METHOD_OF_DECLARE

With the newly introduced CPU_METHOD_OF_DECLARE is not necessary anymore
to reference the relevant smp_ops in the board file, but instead it can
simply be set by the enable-method property of the cpu nodes.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Olof Johansson <olof@lixom.net>

arch/arm/boot/dts/rk3066a.dtsi

@@ -24,6 +24,7 @@
 	cpus {
 		#address-cells = <1>;
 		#size-cells = <0>;
+		enable-method = "rockchip,rk3066-smp";
 
 		cpu@0 {
 			device_type = "cpu";

arch/arm/boot/dts/rk3188.dtsi

@@ -24,6 +24,7 @@
 	cpus {
 		#address-cells = <1>;
 		#size-cells = <0>;
+		enable-method = "rockchip,rk3066-smp";
 
 		cpu@0 {
 			device_type = "cpu";