clk: ux500: Adapt PRCMU and PRCC clocks for common clk

First version of common clock implementation of PRCMU clocks
and PRCC clocks for ux500 platforms.

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>