The clock-tree contains clocks that should never get disabled automatically.
One example are the base ACLKs, the base supplies for all peripherals.

Therefore add a structure similar to the sunxi clock-tree to protect these
special clocks from being disabled.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Tested-by: NDoug Anderson <dianders@chromium.org>
Tested-by: NKever Yang <kever.yang@rock-chips.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>