ASoC: Intel: sof_cs42l42: shrink platform id below 20 characters

The platform_id is too long and is flagged by a sparse warning:

sound/soc/intel/boards/sof_cs42l42.c:483:25: error: too long
initializer-string for array of char(no space for nul char)

fix by using the 'mx' acronym for Maxim

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Paul Olaru <paul.olaru@oss.nxp.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Link: https://lore.kernel.org/r/20210511213707.32958-4-pierre-louis.bossart@linux.intel.com


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