clk: ux500: First version of clock definitions for ux500

In this first version of the clock definitions, the structure for
ux500 are set. Support for u8500, u9540 and u8540 are prepared.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>