OMAP: McBSP: Provide functions for ASoC frame syncronization

ASoC has an annoying bug letting either L or R channel to be
played on L channel. In other words, L and R channels can
switch at random. This provides McBSP funtionality that may
be used to fix this feature.

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