ASoC: Ux500: Control apb clock

When switching to common clock driver for ux500 this clock needs to
be handled as well. Before this clock was internally managed by the
clock driver itself.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>