The Rockchip PX30 SoC has three I2S controllers, i2s1 and i2s2 are
2-channel I2S/PCM controllers handled by the same controller driver, and
i2s0 a 8-channel I2S/PCM/TDM controller handled by another controller
driver.

This adds the device tree node required to enable I2S0 on PX30.

This was tested in a 2-channel I2S with TX BCLK/LRCK for both TX and RX
(rockchip,trcm-sync-tx-only) setup on a soon-to-be-released board.
Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
Link: https://lore.kernel.org/r/20220916091746.35108-1-foss+kernel@0leil.netSigned-off-by: Heiko Stuebner <heiko@sntech.de>