ASoC: Intel: skl_hda_dsp_generic: Update Kconfig documentation

The Kconfig documentation for SND_SOC_INTEL_SKL_HDA_DSP_GENERIC_MACH
is a bit misleading as it refers to a set of older platforms,
while in practise this machine driver supports all modern
Intel systems with Smart Sound Technology based DSP and HDA codecs.

Modify the Kconfig text to reflect current state.

Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210621194057.21711-11-pierre-louis.bossart@linux.intel.com


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