ASoC: SOF: imx: imx8ulp: declare ops structure as static

Sparse warning:

sound/soc/sof/imx/imx8ulp.c:416:24: error: symbol 'sof_imx8ulp_ops'
was not declared. Should it be static?
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20220823154027.762889-1-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/imx/imx8ulp.c

@@ -413,7 +413,7 @@ static int imx8ulp_dsp_set_power_state(struct snd_sof_dev *sdev,
 }
 
 /* i.MX8 ops */
-struct snd_sof_dsp_ops sof_imx8ulp_ops = {
+static struct snd_sof_dsp_ops sof_imx8ulp_ops = {
 	/* probe and remove */
 	.probe		= imx8ulp_probe,
 	.remove		= imx8ulp_remove,