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.com


Signed-off-by: Mark Brown <broonie@kernel.org>