ASoC: tlv320dac33: Add option for keeping the BCLK running

Platform data option for the codec to keep the BCLK clock
continuously running in FIFO modes (codec master).

OMAP3 McBSP when in slave mode needs continuous BCLK running
on the serial bus in order to operate correctly.

Since in FIFO mode the DAC33 can also shut down the BCLK clock
and enable it only when it is needed, let the platforms decide
if the CPU side needs the BCLK running or not.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>