ASoC: fsi: add fsi_pointer_update() for common pointer method

fsi PIO/DMA handler are using each own pointer update method,
but these can be share.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
1 file changed