arm64: dts: rockchip: Add i2s1 on rk356x

This adds the necessary device tree node on rk3566 and rk3568
to enable the I2S1 TDM audio controller.

I2S0 has not been added, as it is connected to HDMI and there is
no way to test that it's working without a functioning video
clock (read: VOP2 driver).

Signed-off-by: Nicolas Frattaroli <frattaroli.nicolas@gmail.com>
Link: https://lore.kernel.org/r/20211016105354.116513-4-frattaroli.nicolas@gmail.com


Signed-off-by: Heiko Stuebner <heiko@sntech.de>