ASoC: sunxi: Add Allwinner H6 Digital MIC driver

The Allwinner H6 and later SoCs have an DMIC block
which is capable of capture.

Signed-off-by: Ban Tao <fengzheng923@gmail.com>
Tested-by: Samuel Holland <samuel@sholland.org>
Link: https://lore.kernel.org/r/1662965133-9232-1-git-send-email-fengzheng923@gmail.com


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