ALSA: Fix OMAP24xx EAC codec port I2S master/slave support

- Add explicit I2S master and slave modes
- Do not configure bit-clock and frame sync direction according to polarity
  changed I2S mode as it was done in programming model but according to
  master/slave mode
- Activate codec port transparent DMA only when EAC is I2S slave

Signed-off-by: Jarkko Nikula <jarkko.nikula@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>