OMAP: McBSP: Wakeups utilized

This patch enables the smart idle mode while
McBPS is being utilized. Once it's done,
force idle mode is taken instead. Apart of it,
it also configures what signals will wake mcbsp up.

Signed-off-by: Eero Nurkkala <ext-eero.nurkkala@nokia.com>
Signed-off-by: Eduardo Valentin <eduardo.valentin@nokia.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>