ASoC: nau8824: Add a nau8824_components() helper

ASoC: nau8824: Add a nau8824_components() helper

Some devices using the NAU8824 have only one speaker. To still have things
working properly this requires the left + right channels to both be mixed
to the left speaker output.

This mixer setup is done by userspace based on UCM profiles. But this
requires userspace to know that there is a mono-speaker. Add a helper
function (for the machine driver) to get a components string providing
this info.

This is done inside the codec driver because the codec driver already
has a DMI quirk table.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20211002211459.110124-3-hdegoede@redhat.com
Signed-off-by: Mark Brown <broonie@kernel.org>