LF-3218-1 ASoC: SOF: imx: Fix PM sleep
This is similar with the refactor for i.MX8MP added in commit
ba2d283f5d9 ("LF-3026-2 ASoC: SOF: imx8m: Remove internal
priv->suspended variable").
Because SOF state machine assumes that even if the DSP wasn't previously
active at a System resume, will re-load the firmware we need to make sure
that all needed resources are active.
Kernel core will take care of enabling the PD, we need to make sure that
we request the MU channels.
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>