ASoC: dt-bindings: nau8825: Add delay control for input path

Change the original fixed delay to the assignment from property. It will make
more flexible to different platforms for avoiding pop noise at the beginning
of recording.

Signed-off-by: David Lin <CTLIN0@nuvoton.com>
Link: https://lore.kernel.org/r/20230414103941.39566-1-CTLIN0@nuvoton.com
Signed-off-by: Mark Brown <broonie@kernel.org>