ASoC: dt-bindings: renesas: rsnd: Fix incorrect 'port' regex schema

ASoC: dt-bindings: renesas: rsnd: Fix incorrect 'port' regex schema

A property regex goes under 'patternProperties', not 'properties'
schema. Otherwise, the regex is interpretted as a fixed string.

Fixes: 17c2d247ddd2 ("ASoC: dt-bindings: renesas: rsnd: tidyup properties")
Cc: Mark Brown <broonie@kernel.org>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: alsa-devel@alsa-project.org
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210715185952.1470138-1-robh@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>