ASoC: fsi: Modify over/under run error settlement

In current FSI driver, playback function cares only overrun,
and capture function cares only underrun.

But playback function should had cared about underrun,
and capture function should had cared about overrun too.

Signed-off-by: Kuninori Morimoto <morimoto.kuninori@renesas.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>