Documentation,ICE1724 driver,ICE1712 driver
- added model module option to specify board model to snd-ice1712 and snd-ice1724
  drivers.
- removed ez8 option from ice1724.  this can be specified as 'model=ez8' option.
- rewritten some struct init in C99 style.
- function for accessing i2c of ice1724 (for future use).