ARM: dts: rockchip: convert rk3288 device tree files to 64 bits

In order to be able to use more than 4GB of RAM when the LPAE is
activated, the dts must be converted in 64 bits.

Signed-off-by: Tao Huang <huangtao@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>