ASoC: dt-bindings: renesas, rsnd: Group tuples in playback/capture properties

To improve human readability and enable automatic validation, the tuples
in "playback" and "capture" properties in sound device nodes should be
grouped using angle brackets.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20210204130022.1646427-1-geert+renesas@glider.be


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