ASoC: SOF: imx: Add code to manage DSP related clocks

We need at least 3 clocks in order to power up and access
DSP core registers found on i.MX8QM, i.MX8QXP and i.MX8MP
platforms.

Add code to request these clocks and enable them at probe. Next
patches will add PM support which will only activate clocks when
DSP is used.

DSP clocks are already documented in
Documentation/devicetree/bindings/dsp/fsl,dsp.yaml

We choose to add:
	* imx8_parse_clocks
	* imx8_enable_clocks
	* imx8_disable_clocks

wrappers because in the future DSP will need to take care about the
clocks of other related Audio IPs (e.g SAI, ESAI).

Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Reviewed-by: Paul Olaru <paul.olaru@oss.nxp.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20211119094319.81674-2-daniel.baluta@oss.nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>