ASoC: Samsung: Add common I2S driver

The I2S controllers since S3C64XX are incremental revisions, with
a new feature added to the last one. The programming i/f doesn't
conflict between these revisions, so it is possible to have one
common driver that could manage various versions of I2S (v3, 4 & 5)

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