The 'I2S' example configures the I2S port to transmit audio.

Configuration:
- The I2S port uses P0.10, P0.11, P0.12 and P0.13 for I2S audio
- I2S_BCLK: P0.12
- I2S_LRCLK: P0.13
- I2S_SDO: P0.11
- I2S_SDI: P0.10

Functionality:
 - The example configures the I2S port and uses DMA to transmit
   the audio.
 - The program starts by transmitting the audio, then mutes the output,
   pauses the output and unpauses the output.
