clk: ux500: Clock definitions for u8500

First version of clock definitions of PRCMU and PRCC clocks
for the u8500 platform.

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>