ASoC: omap-pcm: Correct dma mask

DMA_BIT_MASK of 64 is not valid dma address mask for OMAPs, it should be
set to 32.
The 64 was introduced by commit (in 2009):
a152ff24 ASoC: OMAP: Make DMA 64 aligned

But the dma_mask and coherent_dma_mask can not be used to specify alignment.

Fixes: a152ff24 (ASoC: OMAP: Make DMA 64 aligned)
Reported-by: Grygorii Strashko <Grygorii.Strashko@linaro.org>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org