ASoC: Intel: nau8825/rt5682: move speaker widget to common modules

ASoC: Intel: nau8825/rt5682: move speaker widget to common modules

Two machine drivers sof_rt5682 and sof_nau8825 always register two
speaker widgets 'Left Spk' and 'Right Spk' regardless the actual
number of speakers. Move the widget registration to speaker common
modules to avoid useless speaker widgets for 1 or 4 speaker boards.

Reviewed-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Brent Lu <brent.lu@intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20240426152529.38345-2-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>