ASoC: fsl_rpmsg: Add rpmsg audio support for i.MX8ULP

On i.MX8ULP the audio interface and codec are controlled
by Cortex-M domain, Cortex-M core provides audio service
over rpmsg.

The rpmsg audio function is almost same as i.MX7ULP
platform, so share same configuration.
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Link: https://lore.kernel.org/r/1632972413-22130-1-git-send-email-shengjiu.wang@nxp.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/fsl/fsl_rpmsg.c

@@ -174,6 +174,7 @@ static const struct of_device_id fsl_rpmsg_ids[] = {
 	{ .compatible = "fsl,imx8mm-rpmsg-audio", .data = &imx8mm_data},
 	{ .compatible = "fsl,imx8mn-rpmsg-audio", .data = &imx8mn_data},
 	{ .compatible = "fsl,imx8mp-rpmsg-audio", .data = &imx8mp_data},
+	{ .compatible = "fsl,imx8ulp-rpmsg-audio", .data = &imx7ulp_data},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, fsl_rpmsg_ids);