ASoC: dt-bindings: renesas,rsnd.yaml: add R-Car Gen4 support

ASoC: dt-bindings: renesas,rsnd.yaml: add R-Car Gen4 support

There are no compatible for "reg/reg-names" and "clock-name"
between previous R-Car series and R-Car Gen4.

"reg/reg-names" needs 3 categorize (for Gen1, for Gen2/Gen3, for Gen4),
therefore, use 3 if-then to avoid nested if-then-else.

Move "clock-name" detail properties to under allOf to use if-then-else
for Gen4 or others.

Link: https://lore.kernel.org/all/87zg9vk0ex.wl-kuninori.morimoto.gx@renesas.com/#r
Link: https://lore.kernel.org/all/87r0v2uvm7.wl-kuninori.morimoto.gx@renesas.com/#r
Link: https://lore.kernel.org/all/87r0v1t02h.wl-kuninori.morimoto.gx@renesas.com/#r
Link: https://lore.kernel.org/all/87y1p7bpma.wl-kuninori.morimoto.gx@renesas.com/#r
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/87sffa8g99.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>