ASoC: S3C: Fix PCM TXFIFO_DIPSTICK value

This patch modify FIFO_DIPSTICK value of PCM TX FIFO to be a optimal one.
Privious value (0x20) did not support 'Almost_full' of PCM FIFO for the DMA
request.

Signed-off-by: Seungwhan Youn <sw.youn@samsung.com>
Acked-by: Jassi Brar <jassi.brar@samsung.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>