ASoC: codecs: Rename "sync-flag" to "awinic,sync-flag"

Rename "sync-flag" to "awinic,sync-flag", this is to be
consistent with the "awinic,aw88395.yaml" file

Signed-off-by: Weidong Wang <wangweidong.a@awinic.com>
Link: https://lore.kernel.org/r/20230928105727.47273-9-wangweidong.a@awinic.com


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