MLK-18497-10: ASoC: fsl: dsp: Refactor fsl_dsp_{open|close}

DSP driver now supports two interfaces. Old ioctl chardev based
interface and ALSA compress interface.

Because some part of the open/close code is common introduce
two new functions which encapsulate the common functionality.

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 61d764aa7352e135f7c700689c9266aa255445b0)
Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com>
Signed-off-by: Srikanth Krishnakar <Srikanth_Krishnakar@mentor.com>
Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com>