ASoC: dt-bindings: awinic,aw88395: Add properties for multiple PA support

ASoC: dt-bindings: awinic,aw88395: Add properties for multiple PA support

Add two properties, the "awinic,audio-channel" property and the
"awinic,sync-flag". The "awinic,audio-channel" is used to make
different PA load different configurations, the "awinic,sync-flag"
is used to synchronize the phases of multiple PA. These two properties
will be read by the corresponding driver, allowing multi-PA to
achieve better playback effect.

Signed-off-by: Weidong Wang <wangweidong.a@awinic.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230928105727.47273-2-wangweidong.a@awinic.com
Signed-off-by: Mark Brown <broonie@kernel.org>