dt-bindings: mmc: dw-mshc-hi3798cv200: convert to YAML

convert the legacy txt binding to modern YAML and rename to
hisilicon,hi3798cv200-dw-mshc.yaml. No semantic change.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Yang Xiwen <forbidden405@outlook.com>
Link: https://lore.kernel.org/r/20240229-b4-mmc-hi3798mv200-v7-3-10c03f316285@outlook.com


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>