ASoC: S3C64XX: I2S: Make BCLK independent of sample size

For some CPU-CODEC and source clock combination we might need to set
BCLK to N*Sample_size*LRCLK, where N may be even 3 or 4, not just 2.

We can simply remove the dependency of BCLK on sample size as there
is already a callback(S3C_I2SV2_DIV_BCLK) available to set required BCLK.

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>