riscv: dts: canaan: use custom compatible for k210 i2s

riscv: dts: canaan: use custom compatible for k210 i2s

The devicetrees using the Canaan k210 all have a sound-dai-cells value
of 1, whereas the standard binding example for the DesignWare i2s and
other use cases suggest 0. Use a k210 specific compatible which
supports this difference.

Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20220705215213.1802496-10-mail@conchuod.ie
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>