ASoC: Fix data format configuration for S3C64xx IISv2 and add 24 bit

The data format configuration for S3C64xx IISv2 is completely different
to that for S3C24xx. Instead of a single bit configuration in bit 0 of
IISMOD we have format selection in bits 13 and 14 and bit clock rate
selection in bits 1 and 2. While we're here add support for 24 bit
samples in S3C64xx.

At some point it may be desirable to expose the bit clock rate selection
to users but given the limited configuration options that may not be
required.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>