ARM: rockchip: add rk3288 basic smp support

TEST: get log:
[    0.129087] Brought up 4 CPUs
[    0.165528] SMP: Total of 4 processors activated.

TODO:
seems some bug in rk github 3.14_kernel.
disable temporary, enable following item to enable smp.
//              enable-method = "rockchip,rk3288-smp";

commit from heiko:
918b1c27b9f20e3aeb914589bcf84546312261ad

Change-Id: I656956399dae7a263e048fa4ed6e58f24061489e
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>