NXP LPA(Low Power Audio) DSP

The DTS is for i.MX8MP DSP offload audio playback. DSP only use OCRAM
and OCRAM_A when audio playback, so DRAM can enter retention mode to
save Power. As the size limitation of OCRAM and OCRAM_A and the size
audio decoder library, the LPA playback only can support MP3.
OCRAM address is 0x900000-0x990000. ATF will use 0x960000-0x980000.
DSP LPA will use ocram(0x900000-0x960000) and ocram_e(0x980000-
0x990000)

Required properties:

  - compatible			: Contains "fsl,imx8mp-dsp-lpa".
  - fsl,dsp-firmware		: LPA DSP FW name.

Example:

&dsp {
	compatible = "fsl,imx8mp-dsp-lpa";
	ocram = <&ocram>;
	ocram-e = <&ocram_e>;
	fsl,dsp-firmware = "imx/dsp/hifi4_imx8mp_lpa.bin";
	status = "okay";
};