arm: dts: rockchip: rk3288: move to 64 bit reg size

To make automatic Rockchip DT syncing possible from Linux to U-boot prepare
rk3288.dtsi by moving to 64 bit reg size.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/mach-rockchip/Kconfig b/arch/arm/mach-rockchip/Kconfig
index b577a91..6ff0aa6 100644
--- a/arch/arm/mach-rockchip/Kconfig
+++ b/arch/arm/mach-rockchip/Kconfig
@@ -125,6 +125,7 @@
 	select SUPPORT_SPL
 	select SPL
 	select SUPPORT_TPL
+	select FDT_64BIT
 	imply PRE_CONSOLE_BUFFER
 	imply ROCKCHIP_COMMON_BOARD
 	imply SPL_ROCKCHIP_COMMON_BOARD