MLK-18497-12: ASoC: fsl: imx-dsp: Add DSP machine driver

Finally! We register DSP as a sound card.

Reviewed-by: Cosmin-Gabriel Samoila <cosmin.samoila@nxp.com>
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
(cherry picked from commit 3e993bbaa64fb366fc99650a7f837e30fa1b466d)
(Vipul: Fixed merge conflicts)
Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com>