ASoC: SOF: Intel: Provide debugfs_add_region_item ops for core

Set the generic iomem callback for debugfs_add_region_item to avoid
regression when the core switches to use the generic interface for
the regions.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Daniel Baluta <daniel.baluta@gmail.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Link: https://lore.kernel.org/r/20210915122116.18317-11-peter.ujfalusi@linux.intel.com


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