ASoC: Intel: Skylake: Use correct function to access iomem space

For copying from __iomem, we should use __ioread32_copy.

reported by sparse:
sound/soc/intel/skylake/skl-debug.c:437:34: warning: incorrect type in argument 1 (different address spaces)
sound/soc/intel/skylake/skl-debug.c:437:34:    expected void [noderef] <asn:2> *to
sound/soc/intel/skylake/skl-debug.c:437:34:    got unsigned char *
sound/soc/intel/skylake/skl-debug.c:437:51: warning: incorrect type in argument 2 (different address spaces)
sound/soc/intel/skylake/skl-debug.c:437:51:    expected void const *from
sound/soc/intel/skylake/skl-debug.c:437:51:    got void [noderef] <asn:2> *[assigned] fw_reg_addr

Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@intel.com>
Link: https://lore.kernel.org/r/20190827141712.21015-2-amadeuszx.slawinski@linux.intel.com
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org