ARM/ASoC: omap-mcbsp: Move OMAP2+ clock parenting code to ASoC driver

Move the McBSP CLKS re-parenting code to ASoC driver from
arch/arm/mach-omap2.
The call fort the re-parenting has been already limited to OMAP2+ SoC in
the ASoC driver. There is no longer need to have callback function for it.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>