clk/ARM: move Ux500 PRCC bases to the device tree

The base addresses for the Ux500 PRCC controllers are hardcoded,
let's move them to the clock node in the device tree and delete
the constants.

Cc: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Michael Turquette <mturquette@baylibre.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>