ASoC: fsl: remove use of imx-fiq-pcm-audio from imx-ssi

Rather than instantiating imx-fiq-pcm-audio to call imx_pcm_fiq_init(),
imx-ssi can just directly call it to save the use of imx-fiq-pcm-audio.
With this change, imx-ssi becomes not only a cpu DAI but also a platform
device, so updates platform device setup in eukrea-tlv320, phycore-ac97
and wm1133-ev1 accordingly.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>