ASoC: simple-card: Merge single and muti DAI link(s) code.

This patch will split the DT node into old style and new style:
The new style will merge the single DAI link and muti DAI links code
together, the new style will be easier to add muti DAI links from old
single DAI link DTs.

This patch will maintian compatibility with the old DTs.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>