This adds the device-node and config select to enable the
scu in all Rockchip Cortex-A9 SoCs.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Tested-by: NUlrich Prinz <ulrich.prinz@googlemail.com>

RK2928 and RK3066 contain a dw_apb timer component, while the rk3188 uses
a slightly similar but still different timer component. But all of them
support the ARM-global-timer that got added as clocksource driver recently.

So enable support for it to get a working clocksource for rk3188.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>

The rk3188 SoC shares a lot of peripherals with the rk3066 SoC,
but not all. Therefore move the common parts to a shared dtsi.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>