ASoC: dt-bindings: hisilicon: Convert hi6210 I2S to dt-schema

ASoC: dt-bindings: hisilicon: Convert hi6210 I2S to dt-schema

Convert the Hisilicon hi6210 I2S controller hardware binding from
legacy plain text to modern YAML dt-schema format.

During the conversion, the order of the dma-names properties in the
example was corrected to "tx", "rx" to match the official property
description, resolving a contradiction in the original text binding.

Signed-off-by: Chaitanya Sabnis <chaitanya.msabnis@gmail.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20260327092106.4233-1-chaitanya.msabnis@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>