ASoC: da7219: Update DAI clock binding info to cover WCLK/BCLK

With the need to expose WCLK and BCLK as separate clocks, the
'clock-cells' and 'clock-output-names' descriptions need to be
updated as now the codec is providing 2 clocks. The example is
also updated accordingly.

Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Mark Brown <broonie@kernel.org>