ASoC: rt1015: fix the first word being cut off

This patch adds a control that there are four options to control the digital volume output.
The user could select "immediate" to make volume updates immediately.
In default, the driver selects the volume update with "zero detection + soft inc/dec change".

Signed-off-by: Shuming Fan <shumingf@realtek.com>
Link: https://lore.kernel.org/r/20230915020530.83452-1-shumingf@realtek.com


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