The DSP format wasn't still correct in OMAP McBSP DAI even after the commit
bd25867a.

Thanks to Peter Ujfalusi <peter.ujfalusi@nokia.com> for noticing and being
part of the fix. Now the FS length definition is more clear by defining
it with  FWID(0).
Signed-off-by: NJarkko Nikula <jarkko.nikula@nokia.com>
Acked-by: NPeter Ujfalusi <peter.ujfalusi@nokia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>